Optimization of machining processes from the perspective of energy consumption: A case study

Virtual manufacturing systems provide a useful means for products to be manufactured 'right the first time' without the need of physical testing on the shop floor. Earlier research was mostly on developing a virtual manufacturing environment. Over the years, simple graphical prediction and simulation gave way to complex multi-science predictions. Virtual systems such as Virtual Machine Tool, Virtual Machining, Virtual Assembly, Virtual Tooling and Virtual Prototype have been developed to support virtual manufacturing. Different systems and approaches have different targeted applications. This paper aims to provide a comprehensive review of existing virtual systems. Their focuses and approaches (i.e. virtual reality, Web-based techniques, mathematical modelling, hardware interactions and STEP-NC-based methodologies) are discussed in detail. To better understand the systems, we have categorized them into different groups according to their application domains. Discussions and concluding remarks are given based on the review.

Review: Virtual machine tools and virtual machining-A technological review

Recently, some activities for environmental protection have been attempted to reduce environmental burdens in many fields. The manufacturing field also requires such reduction. Hence, a prediction system for environmental burden for machining operation is proposed based on the Life Cycle Assessment (LCA) policy for the future manufacturing system in this research. This system enables the calculation of environmental burden (equivalent CO2 emission) due to the electric consumption of machine tool components, cutting tool status, coolant quantity, lubricant oil quantity and metal chip quantity, and provides accurate information of environmental burden of the machining process by considering some activities related to machine tool operation. In this paper, the development of the prediction system is described. As a case study, two Numerical Control (NC) programs that manufacture a simple shape are evaluated to show the feasibility of the proposed system.

https://www.jstage.jst.go.jp/article/jsmec/49/4/49_4_1188/_pdf

Development of Prediction System for Environmental Burden for Machine Tool Operation

We have developed an environmental burden analyzer for machine tool operations, which can evaluate an NC program from the view point of an environment burden by simulating a cutting process and using emission intensities. In this paper, global warming is selected as an impact category and the environmental burden analysis of dry, wet and MQL machining operations are carried out by using this analyzer with consideration of various situations. The influence of the peripheral devices of a machine tool, the spindle and the servo motors, the coolant, the lubricant oil, the cutting tool and the metal chips to global warming is introduced in detail.

Environmental Burden Analysis for Machining Operation Using LCA Method

At present, before real factories are implemented on the shop floor, methods to evaluate facility control programs for equipment, such as ladder programs for programmable logic controllers (PLC) while mixing and synchronizing real equipment and virtual factory models on the computers, have not been developed Digital data as virtual factory models which are defined at a design stage cannot be re-used at an implementation stage These difficulties stop precise and rapid support of a manufacturing system engineering process from the design stage to the implementation stage In this paper, an intermediation environment to connect real factories and virtual factories is first proposed This environment consists of a distributed real manufacturing simulation environment (DRMSE) and a distributed simulation environment (DSE) Then DRMSE, which creates evaluating facility control programs while mixing and synchronizing real equipment and virtual factory models before real factories are implemented, is proposed i

Efficient manufacturing system implementation based on combination between real and virtual factory

Automatic Production Planning System to Achieve Flexible Direct Machining

The conceptual architecture of autonomous and intelligent machine tools has been proposed not only to generate flexibly the process and operation plan but also to utilize the machine tools and cutting tools' performance while satisfying the requirements of the products and avoiding unexpected machining trouble. In order to realize the autonomous milling, machining strategy such as tool paths and cutting conditions must be decided, not in advance like current NC machining, but in a real-time manner. The objective of this research is to develop a real time machining optimization with machining simulation. Consequently, a cutting simulation system called a virtual machining simulator has been developed for this purpose. This simulator can calculate the changing geometry of the workpiece and estimate the instantaneous cutting force, torque, etc using the physical model. This estimated information enables the system to decide the suitable cutting conditions according to the machinability evaluated. In this pap...

Real-time cutting simulation system of a milling operation for autonomous and intelligent machine tools

The designer's intention is the essence of design. But the geometric information is the only one that we handle in the conventional CAD system. In this paper, we propose the description model of designers' intention that might be helpful to reduce the troubllesome communications among the designers. The designers' intention is described as the correlation using the required funtions, the binding conditions, the technical information, the connotational assignments and the geometric information. The required functions are represented by a tree structure to show the sequence of designers' consideration. The lowest function is assigned to the functional elements that are selected from the geometric information according to the connotational assignments. Additionally, the binding conditions and the technical information are related to the functional elements. The effective usage of designers' intention model is verified under the redesign process. It shows that the redesign is processed successfully using the designers' intention.

Description Model of Designers' Intention in CAD System and Application for Redesign Process

In order to develop an autonomous and intelligent machine tool, a system named Digital Copy Milling (DCM) was developed in our previous studies. The DCM generates tool paths in real time based on the principle of copy milling. In the DCM, the cutting tool is controlled dynamically to follow the surface of CAD model corresponding to the machined shape without any NC program. In this study, surface roughness control of finished surface is performed as an enhanced function of DCM. From rough-cut to semi-finish-cut and finish-cut operations, the DCM selects cutting conditions and generates tool paths dynamically to satisfy instructed surface roughness Ra. The experimental verification was performed successfully. © 2012 Authors. Published by Elsevier B.V. Selection and/or peer-review under responsibility of Prof. Eiji Shamoto.

Keiichi Shirase

Papers

Automatic Production Planning System to Achieve Flexible Direct Machining

Real-time cutting simulation system of a milling operation for autonomous and intelligent machine tools

Description Model of Designers' Intention in CAD System and Application for Redesign Process

Surface Roughness Control Based on Digital Copy Milling Concept to Achieve Autonomous Milling Operation

Surface Roughness Control Based on Digital Copy Milling Concept to Achieve Autonomous Milling Operation