Collision Reduction Walking for Lower Limb Exoskeletons

Abstract

Lower limb exoskeletons have received considerable interest in strength augmentation, rehabilitation, and walking assistance scenarios. For walking assistance, repetitive and excessive foot-ground impact makes the patient uncomfortable and even leads to secondary damage. In this paper, variable stiffness ankles are used for collision reduction walking, based on which the Step Length-depended Variable Stiffness Planner (SLVSP) is proposed for lower limb exoskeletons. In the SLVSP, ankle stiffness and step length are optimized to reduce the Collision Loss Of Transport (CLOT). In addition, the mechanical energy-based human intention estimator for continuous walking by the SLVSP is proposed. A dynamics simulation verifies the method’s performance, and the results show that the proposed approach is effective.