In order to enrich mechanism models of spatial parallel manipulators

two novel models of 3-DOF parallel manipulators are presented. One of them is composed of two CRR limbs and one SPS limb

another is composed of two CPR limbs and one SPS limb. The main characteristics of the models are its simple mechanism and easy decoupling of inputs. The screw motions and the degree of freedom of the models are discussed first. The solutions are developed for both the inverse and forward kinematics including position

velocity and acceleration analysis. Some numerical examples for the kinematics analysis are pressnted finally.