A novel 2-DOF fully decoupled rotational parallel mechanism and its characteristics

Abstract:

To avoid the difficulties in the kinematics and dynamic analysis, development of control system, and so on brought by the existence of coupling in the parallel mechanism, a novel two degrees of freedom (DOF) rotational decoupled parallel mechanism (DPM) is proposed. The mobility and motion feature of this 2-DOF rotational DPM is analyzed with the constraint screw method, and the number of mobility is calculated by using the Modified Kutzbach-Grübler criterion. The inverse and forward displacement problems of the proposed DPM are solved according to the geometrical relationship. The expression of the Jacobian matrix is deduced with the relational expression between the input and output parameters of the mechanism. And according to the expression of the Jacobian matrix, the decoupled feature of the proposed parallel mechanism is validated. Aiming at different selection of the drive, the singular configuration of the mechanism is analyzed according to the Jacobian matrix. The contents of this paper enrich the configurations of the decoupled parallel mechanisms and should be useful for the further application of the parallel mechanisms.