Stable Control Gait Planning Strategy for A Rehabilitation Exoskeleton Robot

Abstract

Exoskeleton robots have been widely utilized in current rehabilitation field. Because of lacking the ability of self-balance, it often need to be used with a pair of crutches. Thus it is especially important that the exoskeleton robot with crutches maintain stable in different step sizes. In the use of rehabilitation exoskeleton robots, by planning different lengths of the step sizes and changing the position of the crutches, we found that the different step sizes and different support points will have a great impact on the stability of walking. In this paper, through experimental works with the SIAT rehabilitation exoskeleton robot surface formed by the different positions of the crutches. A Zero Moment Point (ZMP) based method is implemented to obtain the center point position of the pressure, and to get a mathematical expression on stability of the human-machine system. Then, by adjusting the pressure of the four support points of the two crutches and the feet of the exoskeleton robot, the step sizes and the position of the crutch can be dynamically adjusted to achieve the most stable motion state. Finally, an appropriate motion step sizes are realized through controlling of exoskeleton motors.