NaVARo II: A New Parallel Robot With Eight Actuation Modes
This article presents a new variable actuation mechanism based on the 3-RPR parallel robot. This mechanism is an evolution of the NaVARo robot, a 3-RRR parallel robot, for which the second revolute joint of the three legs is replaced by a scissor to obtain a larger working space and avoid the use of parallelograms to operate the second revolute joint. To obtain a better spatial rigidity, the leg mechanism is constructed by placing the scissors in an orthogonal plane to the displacement. Unlike the first NaVARO robot, the kinematic model is simpler because there is only one solution to the inverse kinematic model. Surfaces of singularity can be calculated and presented in a compact form. The singularity equations are presented for a robot with a similar base and mobile platform.