Study On Error Modeling And Experiment For A Four-axis Horizontal Machining Center

This thesis deals with some key issues in the security system of accuracy for afour axis horizontal machining center, covering kinematic error modeling, assemblyvariation modeling and error detection experiments. The following contributions havebeen made.(1) Space motion transformation matrixes of functional units are established byusing the homogeneous coordinate transformation matrix method in the ideal or actualcases. Based on the multi-body system kinematics theory, the building motion isabstracting into tool motion chain and workpieces motion chain. Then, the mappingrelationship between the comprehensive error of the tool relative to the workpiecesand geometric error sources is established.(2) The deviation characteristics that affect the assembly accuracy of machinetool are analyzed. Based on the small displacement torsor theory, the mathematicmodel of typical deviation characteristics is established. On the basis of tandemassembly relation, the mathematic transfer model of assembly deviation is establishedto forecast the end assembly accuracy, providing a theoretical basis to optimize theassembly process.(3) The accuracy forecast model for workbench assembly is constructed.Experiment has verified the effectiveness of the proposed modeling method. Someexperiments such as pitch error compensation, circular interpolation detection, verticaldegree identification, rotation accuracy calibration has been conducted by means oflaser interferometer and ball bar, as a support for precision analysis.