Error analysis and accuracy synthesis of new numerical control shoe last machine

To improve the manufacturing precision of the numerical control shoe last machine,a new error-computing method was put forward.Based on the special dendriform topological structure of the numerical control shoe last system and multi-rigid body system theory,a spatial error-calculating model of the system was built.The error distributing law in the whole work space was discussed,and the maximum error position of the system was found.The sensitivities of error parameters were analyzed at the maximum error position,and accuracy synthesis was conducted by using Monte Carlo method.Combined with the error sensitivities analysis,the accuracy of the main parts was distributed.Results show that compared with traditional method,the mean probability obtained by the method is improved from 0.659 2 to 0.702 1 with the maximal volume error being less than 0.05 mm.The method can be used for error analysis and accuracy synthesis of the complex multi-embranchment motion chain system,and improve the system precision of manufacturing.