Energy efficiency of machine tools

Energy efficiency has been classified as one of the key technological advancements necessary for European industries to grow and stay competitive on the global market. Latest developments in this field have been reviewed and compared. Despite of the effort of the scientific community there is still a considerable field for improvement, e.g. regarding synergy of existing methodologies into a coherent multi-level approaches. This work attempts to provide such perspective as well as necessary tools and methods. Firstly, an experimental characterization approach to collect and process relevant energy data and assist in further analysis is introduced. Secondly, a library of energy models of the components is provided and locally optimized energy-per-feature functions are derived. Proposed energy framework is a mean to describe a generic discrete-manufacturing process. System level model, which incorporates knowledge of system performance, reliability, energy-saving policies and machine level energy functions, is proposed. Economical aspects of the system, namely part price, energy cost and inventory cost are included in the analysis. Demonstration and validation of developed methodology is presented on four use cases. They include energy characterization of robotic arm, analysis of power use in a automated lathe, feature-based model of power use in a lathe and analysis of simple manufacturing system, composed of two machines. The work concludes with remarks on possible improvements in energy efficiency and further developments.