Volumetric Error Analysis of a Stewart Platform Based Machine Tool

Striving for greater accuracy, some machine tool manufacturers are developing parallel structures for the next generation machine tool. Therefore, tools are needed to analyze the effect error sources have on this type of structure. A model of a Stewart Platform based machine tool is developed that provides the framework for inclusion of all relevant error sources. An error analysis is presented based on an error model formed through differentiation of the kinematic equations, and a sensitivity analysis is given as a design tool for tolerance allocation during manufacture. Finally, automated error analysis software is demonstrated that graphically depicts position and orientation errors along tool paths and throughout the workspace.