Spherical mechanism for scanning volumetric spaces

Spherical mechanisms with a parallel structure have found widespread application in various industries. They are used to orient objects in space or to process spherical surfaces, in medicine for design and in prosthetics as an artificial joint, as well as in rehabilitation devices. A new spherical mechanism with a parallel structure and three degrees of freedom has been proposed; it is designed for scanning three?dimensional spaces. The new mechanism has increased rigidity, load?bearing capacity, and positioning accuracy. Its compactness and simple design make it in demand in the context of growing demand for high?precision and flexible robotic systems. The direct and inverse problems regarding the positions of the synthesized mechanism have been solved; a special case with a polar coordinate system has been considered. The working area of the new mechanism has been studied, taking into account the limitations imposed by the links.
EDN: IJQNRZ, https://elibrary/ijqnrz

References

[1] Taunyazov T., Rubagotti M., Shintemirov A. Constrained orientation control of a spherical parallel manipulator via online convex optimization. IEEE/ASME Trans. Mechatron., 2018, vol. 23, no. 1, pp. 252–261, doi: https://doi.org/10.1109/TMECH.2017.2774245

[2] Callegari M., Carbonari L., Palmieri G. et al. Parallel wrists for enhancing grasping performance. In: Grasping in robotics. Springer, 2013, pp. 189–219, doi: https://doi.org/10.1007/978-1-4471-4664-3_8

[3] Bai S. Optimum design of spherical parallel manipulators for a prescribed workspace. Mech. Mach. Theory, 2010, vol. 45, no. 2, pp. 200–211, doi: https://doi.org/10.1016/j.mechmachtheory.2009.06.007

[4] Nhan N.H.K., Tung V.D., Kheylo S. et al. Oscillations and control of spherical parallel manipulator. Int. J. Adv. Robot. Syst., 2019, vol. 16, no. 3, doi: https://doi.org/10.1177/1729881419846394

[5] Lahdiri C., Saafi H., Mlika A. et al. Optimal design of a new redundant spherical parallel manipulator with an unlimited self-rotation capability. Robotica, 2025, vol. 43, no. 1, pp. 300–315, doi: https://doi.org/10.1017/S0263574724001851

[6] Lahdiri C., Saafi H., Mlika A. Working mode study of a new spherical parallel manipulator with an unlimited self rotation capability. In: New advances in mechanisms, transmissions and applications. Springer, 2023, pp. 171–179, doi: https://doi.org/10.1007/978-3-031-29815-8_17

[7] Pacheco Quiñones D., Maffiodo D. et al. Joint path planning of the quasi-spherical parallel manipulator. In: Advances in Italian mechanism science. Springer, 2024, pp. 242–248, doi: https://doi.org/10.1007/978-3-031-64553-2_28

[8] Skvortsova V.A., Abdullin R.R., Stepanova A.A. Optimisation of parameters and structure of a parallel spherical manipulator. Kompyuternye issledovaniya i modelirovanie [Computer Research and Modeling], 2023, vol. 15, no. 6, pp. 1523–1534, doi: https://doi.org/10.20537/2076-7633-2023-15-6-1523-1534 (in Russ.).

[9] Walia K., Navaraj W., Breedon P. Generatively optimised compact 3-DoF spherical parallel manipulator with tightly integrated actuators. Front. Mech. Eng., 2025, vol. 11, art. 1629405, doi: https://doi.org/10.3389/fmech.2025.1629405

[10] Djennane M., Eddine Chehaidia S., Yakoub C. et al. Design, analysis, and implementation of a 3-DOF spherical parallel manipulator. IEEE Access, 2024, vol. 12, pp. 52837–52850, doi: https://doi.org/10.1109/ACCESS.2024.3386549

[11] Gong Z., Ning C., Liang J. et al. Design, modeling and analysis of a spherical parallel continuum manipulator for nursing robots. IEEE ICRA, 2024, pp. 17431–17437, doi: https://doi.org/10.1109/ICRA57147.2024.10610046

[12] Kong X., Jin Y. Type Synthesis of 3-DOF multi-mode translational/spherical parallel mechanisms with lockable joints. Mech. Mach. Theory, 2016, vol. 96–2, pp. 323–333, doi: 10.1016/j.mechmachtheory.2015.04.019.

[13] Soltanov S., Roberts R. Design of a novel bio-inspired three degrees of freedom (3DOF) spherical robotic manipulator and its application in human–robot interactions. Robotics, 2025, vol. 14, no. 2, art. 8, doi: https://doi.org/10.3390/robotics14020008

[14] Güzin D., Gezgin E. Development of a spherical parallel manipulator for brain surgery applications: preliminary study on the dynamic analysis and verification. Robotica, 2022, vol. 40, no. 10, pp. 3726–3750, doi: https://doi.org/10.1017/S0263574722000522

[15] Artobolevskiy I.I. Teoriya mekhanizmov i mashin [Theory of mechanisms and machines]. Moscow, Nauka Publ., 1988. 640 p. (In Russ.).