Perceiving and predicting the intended motion with human-machine interaction force for walking assistive exoskeleton robot

Abstract

The characteristic of man in the loop has always brought lots of difficulties for the control of exoskeleton. To solve these, a hybrid control method based on human-machine interaction force (HMIF) is proposed and applied to the control of lower limb exoskeleton in this paper. We innovatively combine ground contact pressure and body contact force together and give full play to their respective advantages. With the virtual modification of human limb impedance properties, the nature of the human body energy saving with exoskeleton is revealed. One of the greatest strengths of this control strategy is that exoskeleton is able to perceive and anticipate the pilot intended motion in real time, thereby decrease the power consumption of pilot and provide most of the strength necessary for human walking. The simulation results demonstrate the feasibility and validity of the proposed control strategy. The exoskeleton can follow the pilot's motion trajectory and minimize the body contact force without the exact dynamic model.