摘要

Energy is a core part for the sustainable development of machine tool industry; its intensity and utilization has become increasingly important with the concern over global climate change. Machine tools, as a vital part of energy consumption, have major significance for energy savings and carbon emissions. To achieve such energy savings, a precise energy model of a machine tool is a primary register to provide decision support for energy efficiency evaluation and optimization. As there are numerous machine tool components and each with its own characteristic energy signature, the energy consumption of a machine tool has a complex multi-source and dynamic characteristic. To describe such characteristic, a new methodology of energy modeling is proposed with the components working states of machine tools. Firstly, the components of a machine tool are divided into two classifications according to their energy characteristics, i.e., time-varying units (TVUs) and non-time-varying units (NTVUs). Secondly, the working states and coupling relationship of TVUs and NTVUs are studied, and a segmented energy modeling method of TVUs and NTVUs is proposed. Thirdly, the work state execution and coupling relationship of TVUs and NTVUs are combined into a description model of machine tools based on the Business Process Model and Notation (BPMN), and the energy data association of the model is also studied. Finally, a case study of computer numerical control (CNC) milling machine is given to verify the effectiveness of the proposed model.