Virtual ground robot for balance control

This paper proposes a Virtual Ground Robot (VGR) that can interact with a human. The proposed Virtual Ground Robot creates a virtual ground, which has three-degree-of-freedom motions in the pitch, the roll and the height directions. The VGR are driven by Series Elastics Actuator(SEA), which enable force control without force sensor. In this paper, two types of training are proposed: Active training and Passive training. In order to implement two types of training, Geometric Posture and Spatial Impedance mode are suggested using control algorithm.