• parallel kinematics machine
  • spherical robot
  • linear brushless actuators


Sphe.I.Ro. (Spherical Innovative Robot) is the prototype of an innovative parallel kinematics machine developed by the Machine Mechanics Group. The kinematics is analogous to that of the I.Ca.Ro. robot, but by means of a different arrangement of the links the mobile platform has three degrees of freedom of pure rotation. The use of linear motors provides high performance in terms of maximum accelerations reachable at the end-effector; furthermore the parallel nature of the robot results in a high structural stiffness. The control system is implemented on a National Instruments platform (Flexmotion board): rotations are obtained through a PID position control and the manipulator interaction with the external environment is managed by an active impedance control.

Prototype of the Sphe.I.Ro robot actuated by three linear brushless motors with high dynamic performance.

Singularity surfaces within the workspace as a function of the laying angles α (rotation around the x axis), β (rotation around the y axis) and γ (torsion around the z axis).

Determinant of the Jacobian matrix of the robot for different α-β pairs at different torsion values γ.


  • Carbonari, L., Bruzzone, L., Callegari, M. “Impedance control of a spherical parallel platform” (2011) International Journal of Intelligent Mechatronics and Robotics, 1 (1), pp. 40-60.
  • Tina, D., Carbonari, L., Callegari, M. “Design and experimentation of a neural network controller for a spherical parallel robot” (2012) ICINCO 2012 – Proceedings of the 9th International Conference on Informatics in Control, Automation and Robotics, 1, pp. 250-255.
  • Carbonari, L., Palmieri, G., Palpacelli, M.-C., Tina, D.  “Modelling and control of a spherical robotic device” (2013) Proceedings of the IASTED International Conference on Modelling, Identification and Control, pp. 427-434.