Analysis and control of whole body dynamic humanoid motion - towards experiments on a roll-and-rise motion

Abstract

We propose that highly dynamic whole-body motions should be analyzed, realized and exploited for extending the capability of humanoid robots in the real world. Such motions are very different from the today's standard humanoid behaviors such as stable ZMP-based biped walking, and upper-body motion assuming the stability of the lower-body. The kind of motions we are interested are not locally stable states. Sometimes they include diverging trajectories. In this paper, we focus on one example of such motions: a roll-and-rise motion, in which the robot stands up in one action from lying state. It first swings up both of its legs high, swings them down, rolling forward and up on both feet, then extends the legs to achieve the standing posture. Analysis of the dynamics governing the motions is carried out, and some boundary conditions for successful motions are presented. Our current goal is to identify essential minimum control laws that assure the success of the task. In search of them, a series of systematic simulation experiments are carried out to plot the parameter regions which define success or failure. Experiments with real adult-size humanoid robot are also presented.