Analysis on Motion Characters for A 3-PRS Parallel Mechanism

摘要

The motion character of a special three degree-offreedom (DOF) parallel mechanism is analyzed by screw theory. This mechanism's significant feature is that the axis of its prismatic pair is parallel to that of its revolute pair in the same limb. Firstly, by analysis, the mechanism's constraint screws are obtained, which leads to motions along the fixedlength links being restricted. Secondly, we get the mechanism's constraint screws' reciprocal productions, namely the mechanism's free motions, which are three screw motions. After that, a numerical example is presented to illustrate the analysis in detail. At last, we draw some conclusions and discuss the future work.