A discrete-event simulation approach to predict power consumption in machining processes

Abstract

Whereas in the past the sustainable use of resources and the reduction of waste have mainly been looked at from an ecological point of view, resource efficiency recently becomes more and more an issue of cost saving as well. In manufacturing engineering especially the reduction of power consumption of machine tools and production facilities is in the focus of industry, politics and research. Before power consumption in machining processes can be reduced it is necessary to quantify the amount of energy needed, to identify energy consumers and to determine the available degrees of freedom for an optimization. Simulation can be an adequate alternative to the measurement of power consumption during machining operation. However, many of the available simulation methods are not suitable for this task. This paper describes an approach based on the discrete-event simulation, which is known mainly from the simulation of logistical systems. It has been adapted to model machining operations and to generate workpiece-specific power consumption profiles and energy footprints. Two-axis turning in a CNC machining centre is shown exemplary. The aim is to provide a basis for further applications such as the simulation, comparison and optimization of power consumption in process chains and production systems in combination with logistical models.

Energy consumption model and energy efficiency of machine tools: a comprehensive literature review

“…simulation is a kind of method that can capture interaction among a variety of dynamic energy flows and resource flows in the machining process (Larek et al, 2011). Traditional manufacturing system simulation may pay more attention to output, production time, man power and equipment resources, but new simulation study taking manufacture system energy consumption into account is rising gradually.…”

Developing a virtual machining model to generate MTConnect machine-monitoring data from STEP-NC

“…The main body system includes control unit, fans, and so on (Larek et al 2011). Operation of a main body assumedly starts with an input of programme identification such as O0001 of Figure 4(a) and turns off with an input of M02 code as in Figure 4(a).…”

“…Avram and Xirouchakis (2011) proposed a theoretical model to evaluate mechanical energy requirements by using an Automatic Programming Tool file. Larek et al (2011) described a discrete-event simulation to generate workpiecespecific power consumption from an NC part programme. Braun and Heisel (2012) developed a modular modelling approach to generate the estimated energy consumption from an NC part programme.…”

A modeling method for hybrid energy behaviors in flexible machining systems

“…This kind of energy behaviors obtained from the constructed CTOPN model describes the energy consumption of the energyconsuming components of machine tools using the detailed energy data. Taking the PL700 as an example, since the past energy data inOP 1 (OPN for object "PL700") is detail, the firing ofat 13 (PL700 starts processing a part) inOP 1 model will remove the token from sp 13 (Machine is waiting for processing) and add the token tosp 16 (Spindle of machine is active). In this way, the detailed energy behaviors of the energy-consuming components of the PL700 are analyzed.…”