Predictive control estimating operator's intention for stepping-up motion by exo-skeleton type power assist system HAL

Generally, the operator's force signal is utilized in the case of the power assist. However, the operator must keep always providing the force in order to obtain the force signal. We have developed an exo-skeleton type power assist system, HAL (Hybrid Assistive Leg) for the walking aid. The purposes of this study are (1) to estimate the operator's action in the initial stage of the motion, (2) to propose the method for realizing the power assist corresponding to the operator's motion. We include the following mechanism into HAL system: (1) the mechanism which estimate the reference input of the bend angle of a joint by using myoelectricity, (2) the mechanism which autonomously generates the motion using phase sequence. For optional steps, experiments were performed to realize the stepping-up motion which reflects the intention of the operator. As the result, HAL started the autonomous motion immediately when the operator intended to start the motion, and stepping-up motion which reflected the intention of the operator was able to be achieved, even if the operator hardly generated the power.