NMPC design for a self-aligning compliant gait rehabilitation robot
Jin Y. Goyal T. Jamwal P.K. Goecke R. Ghayesh M.H. Hussain S.
December 2025Elsevier B.V.
Robotics and Autonomous Systems
2025#194
The application of robotic devices in rehabilitation is proliferating. Such devices’ mechanism design, actuation, and control strategy are essential for effective and successful rehabilitation treatment. This paper investigates the effectiveness of a self-aligning mechanism for a multi-DOFs (Degrees of Freedom) rehabilitation robot. The actuation is provided by lightweight albeit powerful Pneumatic Muscle Actuators (PMA). Although the mechanism design and the actuation system provide a safe, secure, and efficient platform for rehabilitation, they increase the complexity of the system modeling and, subsequently, the control systems design. Furthermore, the mechanism has three active and five passive DOFs, which further increase the intricacies of system identification. Hence, this paper presents an autodidactic approach to identify the system dynamics using the Koopman operator. The learned operator is then integrated with the Nonlinear Model Predictive Controller (NMPC) to guide the robot along the predefined path while adapting to the nonlinear dynamics of the physical human-robot interaction. Finally, the rehabilitation robot and the control scheme were experimentally validated with healthy human subjects. The results demonstrate that the NMPC controller could successfully manipulate the gait rehabilitation robot with the subject to achieve the desired orientation during the entire gait cycle.
Gait rehabilitation robot , Koopman operator , NMPC , Nonlinear dynamics , System Identification
Text of the article Перейти на текст статьи
College of Mechanical Engineering, Zhejiang University of Technology, Zhejiang, Hangzhou, 310023, China
Human-Centred Technology Research Centre, School of Information Technology and Systems, University of Canberra, Bruce, ACT, Australia
Department of Electrical and Computer Engineering, Nazarbayev University, Astana, Kazakhstan
School of Systems and Computing, University of New South Wales, Canberra, 2600, ACT, Australia
School of Electrical and Mechanical Engineering, University of Adelaide, Adelaide, SA, Australia
College of Mechanical Engineering
Human-Centred Technology Research Centre
Department of Electrical and Computer Engineering
School of Systems and Computing
School of Electrical and Mechanical Engineering
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026