Design of Knee Exoskeleton Robot Based on Human Physiology

Abstract

In order to achieve a motion form similar to the human knee structure to better assist the wearer to achieve walking gait motion. In this paper, we propose an anthropomorphic knee-joint exoskeleton robot structure, which adopts similar structural characteristics to the human knee-joint structure and has a variable instantaneous center of rotation (ICR) motion form, and uses a crossed four-link mechanism to simulate the internal cruciate ligament of the human knee joint to achieve multi-axis rotational motion of the knee joint, so that the human joint motion and the exoskeleton motion form can be better matched. The telescopic rod is used to simulate the human thigh muscle to drive the knee exoskeleton flexion and extension movement, and the auxiliary limiting locking mechanism simulates the knee patella to prevent the knee joint exoskeleton over-extension, which improves the coordination with the human joint movement and the adaptability of the wearer. Through simulation experimental analysis, it is verified that the bionic knee exoskeleton has good motion performance compared with uniaxial knee joint in terms of motion morphology and power consumption. Under the condition of satisfying the human knee joint flexion and extension angle and torque, the control learning method is applied to achieve the consistency of motion trajectory between the knee joint exoskeleton and human joint, to ease the wearer’s discomfort in the walking process and improve the wearing comfort of human sports training.