关键词: 三自由度, 并联机器人, 螺旋理论, 型综合, 约束链

Abstract: The configuration design or the structural synthesis is the key factor in parallel robot designs. A new method to synthesize the 3-DOF parallel mechanisms called the constraint accession is proposed according to the screw theory in view of the classification of kinematical chains, where the active kinematical chains control the necessary DOFs and the passive kinematical chains control the unnecessary ones. The relevant active and passive kinematical chains are put forward and the constraint chains are classified in detail. It is demonstrated by an example that new configurations can be obtained by assembling different kinematical limbs. The new method makes the procedure of configuration design simpler and easier. As long as the number of the active chains chosen is the same to that of DOFs and the corresponding constraint chains are chosen reasonably, some new types of PRM can be assembled.