A smart walker based on a hybrid motion model and machine learning method

• Published in: Mechatronics (Oxford) Vol. 96; p. 103069
• Main Authors: Cheng, Jinsai, Shen, Tao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2023
• Subjects: Human robot interaction; Hybrid human motion model; Machine learning algorithm; Smart walker; Human robot interaction; Hybrid human motion model; Smart walker; Machine learning algorithm
• ISSN: 0957-4158; 1873-4006
• DOI: 10.1016/j.mechatronics.2023.103069

Due to the degeneration of musculoskeletal structure and strength, the elderly population is facing significant mobility challenges. Walkers are widely used for mobility-impaired people. In this research, a smart walker has been developed by using a hybrid motion model (HMM) and a machine learning model based on the vertical interaction force to match the velocity between the walker and its user, which can reduce the horizontal interaction force thus to help lower the operational effort. It is equipped with only force sensors on the handlebars as a human-robot interface. The human motion is modeled by using the HMM in which an inverted pendulum model is used in the single support phase and a constant velocity model is used in the double support phase. A novel gait phase detector is built based on a machine learning method to correlate the force information and the walking gait phases. Experiments with three subjects are carried out to verify the effectiveness of the gait phase detection method and the hybrid motion model. The results demonstrate that the walker can accurately identify gait phases with more than 90 % accuracy and the horizontal interaction force is reduced to around 50 % of that under the constant velocity model and power-off condition when using the HMM during walking.