System reliability analysis of NC Equipment based on system failure evolution model

Numerical control (NC) machine tool is typical mechatronics system with complicated failure features. System reliability may be affected by the internal properties, external factors, dynamic physical effects and the complex interdependent relationship, and it is too complicated to accurately model or analyse by conventional methods. Improving the reliability of machine tool cannot rely solely on improving unit parts reliability level, and reliability design should be performed at the system level for a better profit. For this purpose, using agent-oriented modeling method, a system failure evolution model is proposed to simulate the failure dynamic process. With the model, not only system lifetime and reliability can be analyzed, system failure mechanism and impact of the internal properties, external factors and system parameters also can be researched. Unit failure-agent model, system-level failure-agent model, hierarchical model structure and simulation control method are described separately. Finally, an example of the machine tool´s feed system model is given to simulate and analyze system life, and a further analysis indicate that the model is valid and close to the real data.