Abstract: Parameters error transformation method to constructing geome-try error models for parallel micro-manipulators is proposed, and a geometry error model of 6-PSS parallel mi-cro-manipulator with vertical structure is built. Constructing Lagrange conditional extremum equation of its geometry error model, its error sensitivity is analyzed. Finally, the relationship between all kinds of parameter error in the geometry error model is discussed. It is concluded that the former method is simple and effective.

Key words: Error sensitivity, Geometry error model, Parallel micro-manipulator, Parameters error transformation method