Mechanical Design and Experimental verification of a Parallel Hip Exoskeleton with Virtual Rotation Center

Most existing hip exoskeletons have a serial structure that is analogous to the human thigh, which may cause the problem of misalignment between the mechanical joint and biological hip joints during assisted walking, leading to long-term injuries due to the kinematic mismatch and lower wearing comfort. In order to address this problem, a novel hip exoskeleton with parallel structure is developed in this paper. It has a virtual rotation center (VRC) and could transfer misalignment into relative sliding between the thigh cuff and human thigh. A control strategy is developed for appropriate assistance delivery purposes and is verified experimentally based on a preliminary testing platform with a man-made leg. Experimental results have verified the mechanical feature of the exoskeleton and the performance of the controller in assisted walking.