Papers by Author: Da Xing Zeng

Abstract: Deficiencies are existed for currently formulae of mobility calculation for single loop mechanism. It doesn't reflect the constraint imposed to output components by link group. By analyzing the kinematic parameters of link groups, this paper proposes a new method to calculate the mobility of link group, which is the difference of the sum of the degree of freedoms (DOFs) of all the kinematic pairs and the rank of the kinematic parameters of link groups. Also the DOF can be obtained by the total DOFs of link groups and the rank of kinematic parameters of basis point of the output link. It can be concluded that the new method can not only express the move state of the output link, but the constraint imposed to output components by link group also be reflected. The research results can provide a reference for the structural analysis of the single loop.

Abstract: For the real-time pose adjustment of the sub-reflector of antenna to ensure its best condition, Stewart platform-based mechanism is adopted. This paper presents the configuration optimization of the adjusting parallel mechanism taking the minimum force acted on each limb as the target, and the basic structural parameters of the mechanism are obtained. Considering the weight of the moving platform, the external load, and the influence of the snow and the wind, the maximum force acted on the limbs of the mechanism in the required workspace is calculated, which established the foundation for the structural design of the mechanism. The contents of this paper possess theoretical significance and engineering value for the development of the adjusting mechanism for the sub-reflector of antenna.

Abstract: For the general parallel mechanisms(PMS), since the coupling between kinematic chains, the nonlinear relation between the input and output is presented, which have led to difficulty in the trajectory planning and precision control. Design of motion decoupled parallel mechanisms(DPMS) has become a good new topic in this area and has captured researcher's attention. In this work, the approach to a synthesis of three degree-of-freedom(3-DOF) DPMS is considered based on screw theory and motion synthesis ideas. Criterions for type synthesis of the branches for DPMS is established according to the twist screw system of the limbs, which assures the decoupling in each limb. Then a six-step procedure is presented for the type synthesis of 2T1R decoupled mechanisms.