Design of a Rigid-Flexible Hybrid Bionic Lower Limb Robot

Against the backdrop of the intensifying aging population, there exists a large patient population with lower limb movement dysfunctions who require rehabilitation training. Bionic lower limb robots can be used in conjunction with lower limb rehabilitation robot systems based on bilateral control for rehabilitation training. However, traditional rigid serial bionic lower limbs face issues such as large impacts and insufficient control of compliant motion. On this premise, a bionic lower limb robot with a combination of rigid and flexible linkages for remote rehabilitation is proposed, and the following work on its model is carried out: 1) Based on the design concept of rigid-flexible coupling and separated actuator constraints, an overall actuation scheme for the bionic lower limb is established. A dynamic musculoskeletal model of the human body is created using OpenSim to analyze the physiological structure and motion mechanism of the lower limbs. 2) The structure of the bionic lower limb robot is designed according to the size, mass, and degrees of freedom of each joint in the lower limbs. 3) A kinematic analysis based on the Denavit-Hartenberg (D-H) method is conducted for the bionic lower limb robot driven by flexible cables, exploring the relationship between the lower limb motion trajectory and the changes in cable length during the gait motion process. 4) A Lagrangian dynamic model of the bionic lower limb is established, and dynamic simulation is carried out using Adams.