A robust tracking control strategy of omnidirectional lower-limb rehabilitation robot during centre-of-gravity shift

Abstract

With global aging people and patients with lower-limb dysfunction growing, motion control of the omnidirectional lower-limb rehabilitation robot during centre-of-gravity shift is becoming more and more important. This paper proposes a robust trajectory tracking control strategy for omnidirectional lower-limb rehabilitation robot during centre-of-gravity shift. The main contents of this paper consist of three parts: 1) The kinematic and dynamic model that considered centre-of-gravity shift are presented firstly. 2) A robust control strategy with H ∞ tracking performance is developed and used to achieve the desired trajectories. 3) Simulation tests are performed and demonstrate the feasibility and efficacy of the proposed approach.