A Novel Structural Decomposition Method for Error Propagation Mechanism Analysis Based on Meta-Action Unit Theory

A reasonable structural decomposition method is the foundation of studying the error propagation mechanism precisely. In this paper, a new Function-Motion-Action-Part (FMAP) structural decomposition method is proposed to analyze the mapping model between the geometric dimension of part and output errors of a mechanical product. First, the meta-action unit (MAU) theory is extended to the part layer, and the MAU structure and the MAU chain are redefined. Second, according to the coordination characteristics of the parts in MAU, the error expression model of the parts and the error propagation model of the MAU assembly process are established. The state-space model of the MAU output error is further established so as to complete the mapping model from the geometric dimension of manufactured parts to the precision of the MAU. Then, according to the characteristics of the kinematic error propagation between the MAUs, the input and output error indexes of the MAU chain are determined, and the error propagation model in the MAU chain is established based on the radial basis function network. Finally, the methodology is applied to a numerical control rotary table to verify the effectiveness of the FMAP structural decomposition method for the error propagation mechanism analysis.