Design methodology for a novel planar three degrees of freedom parallel machine tool

The dimensional design methodology for a novel planar three degrees of freedom parallel machine tool is investigated. Closed-form solutions are developed for both the inverse and direct kinematics. Based on the formulation of the local dexterity and the definition of the theoretical workspace and valid workspace, the effects of the design parameters on the dexterity and workspace are discussed. The change ratios of condition number and valid workspace were defined and used as the evaluated indicator to analyze the effects of the design parameters on the performances. According to the analysis results, an approach that could satisfy the requirement of the motion platform realizing orientation capability, dexterity and valid workspace is proposed. A design example is given to illustrate the effectiveness of this approach.