A new approach to improving the machining precision based on dynamic sensitivity analysis

摘要

This paper proposes a new approach to improving the machining precision based on dynamic sensitivity analysis. Firstly, the movement transmission chain of machine tools is analyzed to establish the error propagation model. The model can be used to calculate the error sensitive coefficient of each component. Secondly, the deformation of each component is acquired depending on the finite element analysis. Combining the error sensitive coefficient and deformation, the sensitive error components of machine tools are identified. Thirdly, according to the sensitive error components, the layout of the machine tool is modified and the stiffness of sensitive error component is improved to reduce the machining error of machine tools. A simulation example about globoidal cam machine tools is conducted. Comparing the machining error of vertical globoidal cam machine tool and horizontal globoidal cam machine tool in the simulation, the feasibility of the method is verified. This method not only increases the stiffness of the sensitive error component, but also changes the layout of the machine tool based on dynamic sensitivity analysis results. Therefore, it can provide a new approach to improving the machining accuracy. Finally, an experiment was conducted to verify the validity the correctness of the conclusions. (C) 2015 Elsevier Ltd. All rights reserved.