Design and Implementation of 3-RRR Spherical Parallel Robot with Three Coaxial Actuators.

This work, entitled "Design and Implementation of 3-RRR Spherical Parallel Robot with Three Coaxial Actuators" has had the scope to analytically study the kinematics (both inverse and forward one), the workspace and the singularities of a coaxial configuration of a spherical manipulator. The complete 3D design of the robot has been realised, building it thanks to a 3D printing process called FDM Technology (fused deposition modelling). Moreover, it has been modeled a Feed-Forward Position Control, by an external closed-loop in which the motor has been considered as a black-box. In this way, motors have showed less tracking error to follow the cubic position timing law, in Matlab environment. As for the state of the art, this thesis has distanced itself from the literature before, not using a Denavith-Hartenberg's formulation or a loop equation process, in order to describe the kinematics, but investigating on new method, that could be more efficient in a computational terms, and exploiting its peculiar characteristics and functioning. For these reasons, it has been chosen a geometric method to realise the analytical model of the manipulator. This approach has involved only constant and variable squared distances among the relative fundamental points, after defining the parameters of the robot's architecture. Moreover, this method has several features, important to be mentioned, such as being reference frame free, not managing trigonometrical functions, not having recursive elimination of unknowns and getting one equation in one unknown. It is also versatile, because it could be apply to several mechanisms. In the end, these choices, mentioned before, have led to obtain, as a results, a simulation of the robot, in order to better manage it and to focus on the core of both the kinematics and implementations, instead of the traditional process to obtain them.