A digital and structure-adaptive geometric error definition and modeling method of reconfigurable machine tool

摘要

Reconfigurable machine tool (RMT) is designed for mass customization machining and the structure is reconfigured unpredictably due to the wide range of requirements. After reconstruction, accuracy of the new machine tool must be guaranteed firstly, which puts forward higher requirements of flexibility for error definition and modeling. Therefore, a digital and structure-adaptive geometric error definition and modeling method is presented to quickly respond to the structure changes of RMT. The highlight of this method is that the definition and modeling of geometric errors can be realized automatically. Firstly, a coding method is proposed to express the machine tool component with structure and motion information so that the geometric error definition and modeling can be computerized. Then, common expression of the geometric errors considered kinematic and structural attributes is presented. The identification coefficient matrix of geometric error is defined and calculated by using an assignment algorithm according to the configuration tree. At last, geometric error modeling modules are defined and sequential multiplication calculation is presented to establish the geometric error model automatically. Three typical examples are illustrated to verify the correction of digital method. It is the basis of intelligent error compensation of RMT under the market environment of changing demands.