Upright Posture Stabilization by Ground Reaction Force Control

When standing on a slope, a human adjusts his or her posture, i.e., ankle joint angles adjust to the gradient of the slope. In such adaptive behavior, ground reaction forces play an important role. Based on this view, we propose a new posture control law that employs PD and force feedback control, and prove its effectiveness in creating local stability. Applying this control law to a simple robot system, we examine this law's e±ciency. In this experiment, the robot achieves a behavior adaptive to constant external force. Finally, we discuss the possibility of control only using force feedback in consideration of human muscle properties.