This paper presents the design of a novel spherical parallel manipulator. The spherical parallel manipulator consists of three identical limbs and each of them is formed by a planar parallelogram linkage, a universal joint, and a revolute one, successively. Its mobility is analyzed using the reciprocal screws. After that, the kinematics is analyzed in detail, including inverse kinematic modeling, which is validated by a numerical example, inverse Jacobian analysis, singularity analysis, and manipulability analysis, which shows a relatively good performance of force transmission. Then based on the analysis, one prototype is fabricated to validate the effectiveness and feasibility of the design. In the end, some conclusions are drawn and future works are discussed.
GosselinCAngelesJ. The optimum kinematic design of a spherical three-degree-of-freedom parallel manipulator. J Mech Transm Autom Des1989; 111: 202–207.
2.
Gosselin CM and Hamel JF. The agile eye: A high-performance three-degree-of-freedom camera-orienting device. In: Proceedings of 1994 IEEE international conference on robotics and automation, 1994, pp.781–786. New York: IEEE.
3.
VischerPClavelR. Argos: A novel 3-dof parallel wrist mechanism. Int J Robot Res2000; 19: 5–11.
4.
Di GregorioR. Kinematics of a new spherical parallel manipulator with three equal legs: The 3-URC wrist. J Robot Syst2001; 18: 213–219.
5.
Di GregorioR. A new parallel wrist using only revolute pairs: the 3-RUU wrist. Robotica2001; 19: 305–309.
6.
Di GregorioR. The 3-RRS wrist: A new, simple and non-overconstrained spherical parallel manipulator. Trans-Am Soc Mech Engrs J Mech Des2004; 126: 850–855.
7.
Di GregorioR. A new family of spherical parallel manipulators. Robotica2002; 20: 353–358.
8.
Karouia M and Hervé J. A three-DOF tripod for generating spherical rotation. In: Advances in robot kinematics. New York: Springer, 2000, pp.395–402.
9.
Karouia M and Hervé JM. A family of novel orientational 3-dof parallel robots. In: Romansy 14. New York: Springer, 2002, pp.359–368.
10.
LiQHuangZ. A family of symmetrical lower-mobility parallel mechanisms with spherical and parallel subchains. J Field Robot2003; 20: 297–305.
11.
KongXGosselinCM. Type synthesis of three-degree-of-freedom spherical parallel manipulators. Int J Robot Res2004; 23: 237–245.
12.
FangYTsaiLW. Structure synthesis of a class of 3-dof rotational parallel manipulators. IEEE Trans Robot Autom2004; 20: 117–121.
GallardoJRodríguezRCaudilloMet al.A family of spherical parallel manipulators with two legs. Mech Mach Theory2008; 43: 201–216.
16.
Daniali HM, Zsombor-Murray P and Angeles J. The kinematics of 3-dof planar and spherical double-triangular parallel manipulators. In: Computational kinematics. New York: Springer, 1993, pp.153–164.
17.
EnferadiJTootoonchiAA. A novel spherical parallel manipulator: forward position problem, singularity analysis, and isotropy design. Robotica2009; 27: 663–676.
18.
HudaSTakedaYHanagasakiS. Kinematic design of 3-URU pure rotational parallel mechanism to perform precise motion within a large workspace. Meccanica2011; 46: 89–100.
19.
Callegari M, Carbonari L, Palmieri G, et al. Parallel wrists for enhancing grasping performance. In: Grasping in robotics. New York: Springer, 2013, pp.189–219.
20.
Lin R, Guo W and Gao F. Type synthesis of a family of 3-dof spherical parallel mechanisms using upper-lower combination and axis movement theorem. In: Advances in reconfigurable mechanisms and robots II. New York: Springer, 2016, pp.315–326.
21.
EnferadiJShahiA. On the position analysis of a new spherical parallel robot with orientation applications. Robot Comput-Integr Manuf2016; 37: 151–161.
22.
Yang G, Ho H, Lin W, et al. A differential geometry approach for the workspace analysis of spherical parallel manipulators. In: Tian Huang (ed.) 11th world congress in mechanism and machine science, Tianjin, China, 18–21 August 2003, pp.1–4. China: China Machinery Press.
23.
VertechyRParenti-CastelliV. Real-time direct position analysis of parallel spherical wrists by using extra sensors. J Mech Des2006; 128: 288–294.
24.
MerletJP. Parallel robots2012; Vol. 74, New York: Springer Science & Business Media.
25.
HuntKH. Kinematic geometry of mechanisms, London: Oxford University Press, 1978.
MurrayRMSastrySSLiZX. A mathematical introduction to robotic manipulation, Boca Raton, FL: CRC Press, Inc., 1994.
29.
LiJMcCarthyJM. Analysis of two spherical parallel manipulators with hidden revolute joints. J Mech Robot2017; 9: 031007–031007.
30.
KongXGosselinCM. A formula that produces a unique solution to the forward displacement analysis of a quadratic spherical parallel manipulator: The agile eye. J Mech Robot2010; 2: 044501–044501.
31.
YoshikawaT. Manipulability of robotic mechanisms. Int J Robot Res1985; 4: 3–9.
32.
WuGBaiSKeplerJ. Mobile platform center shift in spherical parallel manipulators with flexible limbs. Mech Mach Theory2014; 75: 12–26.
