Evaluation of a stabilizer for biped walk with toe support phase

We discuss a feedback controller to stabilize biped walking which has toe support phase mimicking human gait. Using a reference walking pattern proposed in our previous work [11], our stabilizer can realize reliable walking. To evaluate the quality of stabilization, we propose two indicators, the maximum floor reaction force and the root mean square of the CoM tracking error. From our walking experiments, these indicators suggest us two policies of control parameter tuning, (1) not to control ZMP at toe support, and (2) not to use the ZMP phase-lead compensation for sagittal motion. These findings were validated by simulations of linear inverted pendulum model. It is shown that the observed behavior of the controller is caused by large velocity dissipation at support exchange.