Theory and methodology for kinematic design of Gough-Stewart platforms

The kinematic design issue of Gough-Stewart platforms is investigated. Base d upon a full understanding of the geometrical characteristics of workspace boundary, a spherically-shaped prescribed workspace having a given orienta tion capability is defined for the synthesis of a well behaved workspace. T wo performance measures are presented, i.e. the local dexterity and workspa ce radius ratio. The dimensions of the platform are determined with a prior knowledge of how the design parameters affect the dexterity and workspace radius ratio, resulting in an optimal design in terms of these performance indices. An example of application to the kinematic design of a hexapod mac hine tool is given to illustrate the effectiveness of this approach.