Receding Horizon Based Control of Disturbed Upright Balance with Consideration of Foot Tilting

In some situations, when an external disturbance occurs, humans can rock stably backward and forward by lifting the toe or the heel to keep the upright balance without stepping. Many controlschemes have been proposed for standing balance control under external disturbances withoutstepping. But, in most of them researchers have only considered a flat foot phase. In this paper aframework that includes the foot tilting is presented. This is done by hybrid modeling of the humanoidrobot and also using a receding horizon based approach. The decision for the recovery pattern is donebased on the evaluation of the Vertical Forces criterion. If the method predicts the tilting of the foot under disturbance, then the optimum trajectories are obtained for upper segments to return the robot to the secure posture in which the foot is flat (home posture). The obtained optimum trajectories are then tracked by a feedback controller. In the context of receding horizon approach the Extrapolated Center of Mass position has been used as the stability constraint. The results demonstrate the success of method to reproduce human-like balance recovery reactions under impulsive disturbances. The simulated results are compared with experimental data reported in the biomechanics literature

کلیدواژه ها:

Hybrid Model ، Receding Horizon Approach ، Upright Balance ، External Disturbances