Abstract
This paper studies the stiffness of the parallel cable-driven upper limb rehabilitation robot (PCUR). Firstly, it was derived that the static stiffness expression of the PCUR was composed of platform pose stiffness KT and cable pose stiffness KS. It indicated that the static stiffness of the PCUR was related to the cable tension, the arrangement of the cable, and the cable stiffness. Secondly, a simulation model in MATLAB/Simscape Multibody was built. Cable tension was applied to make the moving platform in a static equilibrium state. The stiffness of the PCUR and the external force on the moving platform were changed, and the motion characteristics of the moving platform were obtained. Finally, the position changes of the moving platform under different external forces were analyzed, and the motion laws of the moving platform under different stiffnesses were summarized.
Highlights
Stroke has become an important issue of global concern due to its high incidence and high disability rate
The corresponding motion results of the moving platform are generated under the cable tension to study the stiffness characteristics of the parallel cable-driven upper limb rehabilitation robot (PCUR) and verify the correctness of the stiffness theory derivation
The cable tensions under different λ were taken to obtain the eigenvalues of the global stiffness matrix K, of which the eigenvalues represent the stiffness values in the six-degrees of freedom (DOF) direction of the space, which are represented by Kx, Ky, Kz, Kα, Kβ, and Kγ, respectively
Summary
Stroke has become an important issue of global concern due to its high incidence and high disability rate. Jin et al designed a three-degree-of-freedom parallel cable-driven robot for upper limb rehabilitation on a flat surface [8]. Research on the stiffness control and force control of the parallel cable-driven upper limb rehabilitation robot (PCUR) can make an overall stiffness adjustment and realize an overall flexibility and a better man–machine interaction of the robot. The PCUR has a simple configuration, an ample working space, and adjustable stiffness, which can meet different upper limb rehabilitation training modes [25,26]. Different training modes need to achieve the best training effect under proper cable tension and stiffness conditions It ensures the safety and comfort of upper limb rehabilitation training. The performances of PCUR under different stiffnesses and the appropriate stiffness of rehabilitation training were analyzed, laying the foundation for the follow-up control of the PCUR’s stiffness
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
