A Family of Novel 2 DOF Rotational Decoupled Parallel Mechanisms

This paper presents a family of novel 2 degree of freedom (DOF) rotational decoupled parallel mechanisms(DPMs). The basic feature of this family is that the moving platform and the fixed base of the DPMs are connected by three limbs, also the motion of the moving platform is decoupled, besides the first and second limbs structure a four-bar linkage or guide bar mechanism. Then we take the UPRUSPS DPM as an example and use the constraint screw method to analyze the motion feature of this DPM. The mobility of the DPM has also been calculated by the Modified Grubler-Kutzbach criterion. At last, the kinematics and decoupled feature of this DPM is analyzed. All the DPMs in this paper are simple and no complicated computation is required for real-time control. So these novel DPMs have very good application value for tracking equipments, such as radar, missile etc. As far as we are aware, this paper puts forward 2 DOF rotational DPMs with three limbs for the first time.