Study on a two-staged control of a lower-limb exoskeleton performing standing-up motion from a chair

Abstract

The paper is concerned with control over a lower-limb exoskeleton device when it performs a sit-to-stand motion from a chair. A mathematical model describing full dynamics of the device is derived, and the strategies to facilitate the desired motion are outlined. A control system based on a modified Jacobian transpose is proposed, and its performance is evaluated in a series of numerical experiments. The simulations proved that the proposed control method can be successfully used to provide stable sit-to-stand motion from a chair.