Individualized Gait Pattern Generation for Sharing Lower Limb Exoskeleton Robot

• Published in: IEEE transactions on automation science and engineering Vol. 15; no. 4; pp. 1459 - 1470
• Main Authors: Wu, Xinyu, Liu, Du-Xin, Liu, Ming, Chen, Chunjie, Guo, Huiwen
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Exoskeletons; Feature extraction; Gait; Gait pattern generation; Gaussian process; Legged locomotion; lower limb exoskeleton robot; Neural networks; Parameters; Pattern generation; Physical factors; Predictions; Regression analysis; Robots; Training; Trajectory; Walking
• ISSN: 1545-5955; 1558-3783
• DOI: 10.1109/TASE.2018.2841358

The development of sharing technology makes it possible for expensive lower limb exoskeleton robots to be extensively employed. However, due to the uniqueness of gait pattern, it is challenging for lower limb exoskeleton robot to adapt to different wearers' gait patterns. Studies have shown that the gait pattern is affected by many physical factors. This paper proposes an individualized gait pattern generation (IGPG) method for sharing lower limb exoskeleton (SLEX) robot. First, the gait sequences are parameterized to extract gait features. Then, the Gaussian process regression with automatic relevance determination is used to establish the mapping relationships between the body parameters and the gait features, and the weights of each body parameters on gait pattern are also given. The gait features of an unknown subject can be predicted based on the training set. Finally, the individualized gait pattern is reconstructed by autoencoder neural network and scaling process based on predicted gait features. The experimental results show that the gait pattern predicted by IGPG is very similar to the subject's actual trajectory and has been successfully applied on the SLEX robot. With the help of sharing technology, the training set will be increased, and the prediction accuracy of individualized gait pattern will also be improved. Note to Practitioners -The main purpose of this paper is to solve the gait pattern mismatch problem when different people wear an lower limb exoskeleton robot. The gait patterns are different for each individual, and the main gait-related factors include body parameters and walking speed (WS). Therefore, the suitable gait pattern for the wearer is predicted according to their body parameters and target WS in this paper. The detailed prediction process and a full analysis of experimental results are also given. Finally, the generated gait patterns are successfully verified on the lower limb exoskeleton robot.