Bionic Mechanical Design and Stair Ascending/Descending Gait Planning of A Lower-limb Exoskeleton Robot

Abstract

A wearable lightweight lower-limb exoskeleton (LLEX) robot that can help paraplegic patients perform daily activities such as standing/sitting, walking, stair ascending/descending is proposed in this paper firstly. In order to ensure comfort between the exoskeleton and the wearer, a novel configuration of the exoskeleton robot that combines active and passive joints, adaptive structure size, and high compatibility with human physiological parameters is proposed. Secondly, this paper proposes a dynamic gait planning algorithm for stairs ascending and descending based on hip and ankle motion position planning, which is implemented to LLEX. It is intended to provide paraplegic patients with personalized gaits for independently ascending/descending stairs of diverse sizes with the help of LLEX. The system employs the inertial measurement unit (IMU) module located on the back to identify the wearer’s movement intention while using the depth camera located on the front of the LLEX to detect heights and depths of different stairs for a dynamic gait. Experiments have been carried out to prove the feasibility and pervasiveness of the gait planning algorithm. The application of LLEX can help patients with various physiological characteristics to complete the task of ascending and descending stairs.