Forward position analysis of a novel three DOF parallel mechanism

A novel three degrees-of-freedom (DOF) parallel mechanism is introduced in this paper. The mechanism consists of a moving platform connected to the base by three branches. Each branch is formed by a close-loop four-bar-linkage mechanism connecting to the moving platform by a S-R dyad. The structural analysis of this mechanism is presented first, and then forward position analysis of the mechanism is addressed. The results are presented in the explicit form. The results show that each structural component of this mechanism subjects to only stretching or compressive forces. The mechanism has the advantages of high rigidity and load carrying capacity, larger working space and good dexterity. This mechanism can be such designed that it can be folded. Because of its structural and kinematic characteristics, the mechanism overcomes the shortcomings of low rigidity of the serial connected open-chain mechanisms and small working space of the six DOF parallel mechanisms. Also, the kinematics of this mechanism is simple and the results are accurate. Therefore, it has prospective practical industry applications, such as industrial robots, fewer DOF flying simulators and parallel machine tools.