**5. Conclusions**

This paper aims to find the optimal design of a planar cable-driven parallel robot for upper limb rehabilitation purposes. For that, an optimization problem was formulated in which the dexterity, the elastic stiffness and the tension in the cables were the chosen criteria. Bounding the cable tensions, avoiding collisions with the mobile platform and controlling the potential positions of the pulleys were the selected constraints. A multiobjective formulation of the optimization design problem showed different nondominated solutions for each pair of criteria, which complicated the selection of a single solution. A mono-objective formulation was then adopted. Weighting coefficients were studied, and appropriate values were selected. Finally, the validation of the robot optimal design was carried out using a real prototype to verify its behavior along the given trajectory. Different

computed errors between the desired and the performed trajectories showed promising results regarding prototype reliability.

**Author Contributions:** Conceptualization, methodology, supervision, writing—review and editing, M.A.L., A.C., J.S., A.M., L.R., S.B., and S.Z.; software and writing—original draft preparation, F.E.; project administration, M.A.L., and A.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was financially supported by the PHC Utique program of the French Ministry of Foreign Affairs and Ministry of higher education, research and innovation and the Tunisian Ministry of higher education and scientific research in the CMCU, project number 19G1121.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Data is contained within the article.

**Conflicts of Interest:** The authors declare no conflict of interest.
