A control of biped robot which applies inverted pendulum mode with virtual supporting point

Abstract

We applied the inverted pendulum mode to the control of a biped robot in order to plan a trajectory in real time. Though the inverted pendulum mode is useful to plan a trajectory, the stability margin of a biped robot is very narrow because of its structural limit. Virtual supporting point (VSP), a new indicator of biped robot control, is suggested with a view to broaden the stability margin of biped robot. Walking parameters could be adjusted by setting VSP without changing other parameters. The mobility of a biped robot is improved compared to the usual method if proper VSP is set. The stable range of VSP is figured out by revealing the relationship between ZMP and VSP. Additionally, biped locomotion could be designed simply and its stability could be determined clearly beforehand by applying VSP. Results of the simulation and the experiment shows the validity of the suggested method.