As the third special issue on Design and Manufacturing for Environmental Sustainability for IJAT, this issue focuses on design and manufacturing theories and methodologies for achieving environmental sustainability and the topic of the special issue seems to be becoming established in this journal.
This special issue contains six articles consisting of a wide variety of rather novel topics emerging in the domain of design and manufacturing for environmental sustainability. The first three deal with design problem in the broader sense: designing of system of systems taking distributed energy generation systems, upgradable design problems, and selection problem of end-of-life products recovery options integrated from the view of environmental load and cost. The last three papers deal with manufacturing problems in the broader sense – motion extraction problems for disassembly automation, machine tool energy efficiency, and optimization problems related to machine tool operating conditions for increasing environmental sustainability. Some papers, revised and extended at the editor’s request, were presented originally at EcoDesign 2015, the ninth international symposium on environmentally conscious design and inverse manufacturing, held in Tokyo, Japan, 2015.
The editor thanks the authors and reviewers for their comprehensive efforts in making this special issue possible and hopes these articles will encourage further research on design and manufacturing for environmental sustainability.
A system of systems (SoS) is a class of complex systems that views multiple and small independent systems as part of a larger and more complex system. Because designing an SoS requires evaluation from a long-term viewpoint, it creates a large uncertainty. While researchers have proposed some robust design methods to handle the uncertainty of systems, they cannot be adopted to SoS design because of the SoS’s strong nonlinearity. This paper first discusses how difficult it is to handle uncertainty of SoS considering the SoS characteristics, and then proposes an approach of robust optimality with lattice points that is simple but plausible to sidestep the issue of nonlinearity. A case study of designing a distributed generation (DG) system, which is a typical SoS, in a Japanese dormitory town is demonstrated in order to verify the proposed approach. The results reveal that this approach helps a designer decide the appropriate amount of subsidy in terms of the robustness of DG installation.
This study proposes an upgradable product design method that falls under the category of “environmentally conscious” product design methods. The method enhances the product’s performance by exchanging or adding only a few of its components. In addition, the proposed method reduces the usage as well as wastage of resources by preventing the disposal of the product itself. This study primarily focuses on manufacturer profit, which was presented as an ill-argued topic in a previous study on upgradable product design methods that potentially provide enhanced sales strategies for upgradable products with an underlying consideration of company sustainability. Moreover, the proposed method in this study assesses how design information uncertainties associated with future prediction (as a ranged value) apply to the concept of set-based design to ultimately obtain ranged sets of design solutions and sales strategies that satisfactorily meet profit, environmental, and functional requirements. Finally, the proposed method obtains ranged design solutions that can realize low environmental loads, low product price, and a highly profitable upgradable product via exclusive application to a multifunctional laser printer scenario. The results of this study indicate the effectiveness of such an upgradable product design method as a vital approach in building a sustainable society.
Conventional production and consumption systems, in which industrial products are manufactured, consumed, and then finally disposed, have significant environmental impacts. Reusing and recycling product components in the manufacture of industrial products has recently become popular as an effective way of conserving natural resources. In this study, we propose a method to assign each product component a reasonable end-of-life (EOL) option (reuse, recycling, and disposal) in the product design phase. We develop a method, in which a product tree is generated by a multi-agent system, to determine EOL options considering component combinations based on environmental impact and incurred cost. In addition, we optimize the disassembly level for better reuse and recycling. The proposed determination method of EOL options for components in a product is justified by numerical examples using an inkjet printer.
Disassembly is one of the key steps for effective treatment of end-of-life products. However, manual disassembly is usually not feasible in industrial practice for reasons of economic infeasibility. Disassembly automation with cognitive ability has been introduced in order to resolve this problem. Execution monitoring is one of the primary functions making the system aware of the current condition and the consequences of execution. A vision system with RGB-D space is used for sensing the conditions of the product in this study.
The European Commission outlined the energy-related products (ErPs) meant to be labelled and regulated in order to achieve the goals to reduce the European amount of CO2-emissions by 20% by 2020 compared to projections. Machine tools (MTs) fulfill all mandatory criteria to be categorized as ErP, namely: significant sales volume, significant environmental impact and significant improvement potential. However, the energy consumption and energy efficiency of MTs strongly depend on their utilization. A generic evaluation approach for quantifying a MT’s energy efficiency is still under development by the working group ISO/TC 39/WG 12, which drives forward the ISO 14955 series for environmental evaluation of MTs.
This work presents an approach for a generic energy efficiency evaluation of MTs. Component-specific behavior is investigated and aggregated in order to entirely describe the power consumption of a MT for any utilization by power mapping. Power maps contain all possible operational scenarios under the condition of the component boundaries. The approach allows a generic MT evaluation independent on the utilization and forms the base for future MT energy efficiency labelling. The presented approach is applied and validated in a practical case study.
This study addresses the strategies for developing the cutting tools used in the material removal process called milling from the viewpoint of sustainable manufacturing. Sustainable manufacturing can be achieved by improving the material, energy, and component efficiencies, simultaneously. Cutting tools are just as important as machine tools and process planning to the achievement of the abovementioned efficiencies. Accordingly, this study describes two strategies based on high cutting velocity and feed per revolution, respectively. Exercising the strategy of high cutting velocity requires a Monte Carlo simulation-driven optimization technique. It helps make a balance between the tool material driven environmental burden and the user-defined maximum allowable cutting velocity. Exercising the strategy of high feed per revolution requires an innovative problem-solving procedure (e.g., TRIZ). It helps create novel solutions (e.g., an oval-shaped milling tool) that eliminate the causes of unstable cutting forces or vibrations when the tool passes over sharp corners. Thus, this study clearly shows that developing a milling tool from the viewpoint of sustainable manufacturing requires a multi-faceted approach. Similar strategies can be used to solve the problems involved in developing other cutting tools.
In this study, we propose an automated design system for an image recognition algorithm applicable to picking work in general and actual factory environments. Considering that an image recognition algorithm design consists of frameworks for selecting a rough recognition method from any of the three basic procedures of pre-processing of contained images, feature-extraction, and discrimination, we formulate it as an optimization problem and propose a random multi-start optimization method by which to derive solutions. We have conducted four types of evaluation experiments for the following four combinations: large or small degrees of similarity in the shape of objects to be recognized and whether they have patterned surfaces. The evaluation experiments show that the proposed design system succeeds in selecting a framework that fits the features of the objects to be recognized and that the designed basic processes have an Fmeasure of 0.9 or more.
This paper presents the wheel life and wear behavior of the cutting edges of a coarse-grained, microdressed cubic boron nitride (cBN) wheel used in mirror-grinding of hardened roll-steel. Many grain-cutting edges with smooth, ductile-mode cut surfaces and numerous brittle-mode-fractured micro dents are formed on the wheel’s working surface after microdressing with a fine-grained diamond dresser. Cylindrical mirror-grinding experiments are conducted using a metal-bonded cBN wheel with a mesh size of #140 (Average grain size da=105μm). A mirror surface with a roughness below 0.2 μm Rz can be efficiently formed with the wheel surface treated by the abovementioned microdressing method. This wheel surface can perform mirror-grinding with precision for more than nine hours. A flat plane formed via attritious wear of the cutting edge gradually extends with increasing accumulated stock removal, and simultaneously, the unevenness due to wear streaks on this flat plane increases. This increase in the unevenness of the worn flat plane is the main factor causing an increase in the roughness of the mirror surface.
Micro-channel chips, which are used in micro total analysis systems, are attracting attention in the medical field. The photolithography technology used in semiconductor manufacturing is generally used to manufacture micro-channel chip dies. However, this technology requires many processes, such as mask fabrication and the application of photoresist to a substrate, as well as expensive clean room facilities. Therefore, this study examines an approach to form a fine groove by cutting with micro-endmills, and experimentally examined a method for reducing the influence of tool run-out on machining accuracy with multi-tooth endmills. As a result, the effects of tool run-out on micro-groove milling, such as a decrease in groove increment, are clarified.
This paper presents a method for in-process detection of tool wear in square end mills. The developed high-speed tool wear detection system uses the contact resistance between the tool and workpiece as a gauge to monitor the progression of tool wear. The electrical resistance decreases with an increase in contact area on the tool flank. In the experiments conducted in our previous study, the target was the face milling process. In the present study, the experiments were conducted on down cut milling with a square end mill. The results are presented based on the observations made on the relationship between the area of tool flank wear and tool-work contact resistance. In conclusion, the results of the experiment show that the present tool wear detection system is effective as an in-process tool wear detection system for square end mills.
We investigated the influence of iron-based workpiece materials on the characteristics of the Si layers by electrical discharge coating. It was found that the chemical elements of the precipitations were uniformly dispersed in the layers on the workpieces containing precipitations a few micrometers in diameter. By contrast, voids occurred in the layer on the workpiece containing bigger precipitations because the precipitations that had not totally melted in the coating process were the starting points of the voids. In addition, the surface of the Si layer on FC250 was extremely rough, and the distribution of the chemical elements of the layer was inhomogeneous. However, the layer was amorphous, and the friction coefficient of the layer was lower than that of the workpiece.
It is well known that chemically strengthened glass plate has excellent strength and hardness properties. These characteristic properties are advantageous for the touch screens used in mobile devices. However, they are detrimental to the process of machining the glass plate. For example, chipping and crack occur around the inlet and outlet of the drilled hole, and the rate of tool wear is significant. Therefore, the surface quality and machining efficiency are low. The drilling process is extremely difficult. In this study, we describe the use of a miniature drilling method to achieve high-quality drilled holes in chemically strengthened glass plate using an electroplated diamond tool with a diameter of 1 mm or less. Using the developed tool with a diameter of 0.5 mm, it is demonstrated that the conventional drilling method can be used to drill a through-hole in the glass plate.
Single-crystal, silicon carbide (SiC) wafers surpass silicon in terms of voltage resistance and heat resistance, and show promise for use in power semiconductor device applications. The aim of this research is to develop a complex machining technology for SiC, which is known to be difficult to process owing to its high hardness. This paper proposes a complex machining method based on converting SiC into a material with a relatively low hardness, and then polishing it using abrasive particles with a higher hardness. The proposed polishing method uses either a photodissociation or an electrochemical technique to reduce the hardness of SiC. The effectiveness of the combined technique is experimentally demonstrated. In addition, a method is proposed for monitoring the processing state by measuring the electric current.
The aim of this study is to develop metallic nanodot arrays with controlled morphology and alignment. To produce gold nanodot arrays with high throughput, the authors propose a new efficient fabrication process based on the templated thermal dewetting method, using a nano-chemical stamping technique with a polymer mold. This process comprises four steps: sputter etching on a quartz glass substrate, patterning of micrometer size by printing with acetone on the substrate by stamping with a polymer film stamp, deposition of a thin Au film on the substrate, and self-organization of the metal nanodot arrays by thermal dewetting. A new method, using a cyclo-olefin polymer film mold for chemical patterning by nano-chemical stamping, was examined. Since the acetone stamped on the substrate reduces the surface energy and affects the contact angle of the gold nanodots, the gold nanodots are distributed along the stamped pattern. It is found that the pattern stamped with acetone on the substrate works as a template for the thermal dewetting process. The nano-chemical stamping technique is useful in controlling the size and distribution of the nanodots.
In the integrally shaping process from a simple material shape to an objective shape, it is necessary to reduce the time required for the machining process in order to improve cost savings and the effectiveness of mass production. For the purpose of achieving high efficiency in the integral shaping from simplicity materials, we have focused on a rough cutting process that requires the most time in the manufacturing process. The purpose of this research is to propose a method for realizing high-speed rough machining using five-axis machine tools with a voxel model, and confirm the high efficiency of the rough cutting. In this research, we use five-axis controlled machine tools for material machining, and suggest two machining methods for the rough cutting process using the voxel model. The first method derives the tool posture where the cutting removal quantity becomes the maximum; this method also carries out a rough cutting process via 3+2 axis controlled machining. The other method carries a complete convex shape that includes the required shape, and simultaneously machines via five-axis machining based on the complete convex shape. This paper demonstrates the 3+2 axis control machining method that uses the voxel model to perform the rough machining process with high efficiency, and the simultaneous five-axis control machining method that uses a complete convex shape model for rough machining. We confirm the results with a computer simulation and actual machining experiments.
We propose a three-dimensional (3D) scanning system based on laser-vision technique and rotary mechanism combination for automatic 3D model reconstruction. The proposed scanning system consists of a laser projector, camera, and turntable. For laser-camera calibration, a new and simple method is applied. The 3D point cloud data of the surface of the scanned object are fully collected by integrating the extracted laser profiles from the laser stripe images corresponding to the rotary angles of the rotary mechanism. The obscured laser profile problem is solved by an additional camera at another viewpoint. From the collected 3D point cloud data, the 3D model of the scanned object is reconstructed based on the facet-representation method. The reconstructed 3D models showed the effectiveness and applicability of the proposed 3D scanning system in many 3D model-based applications.
In industrial fields, it is frequently necessary to measure surface roughness in confined spaces such as boreholes and grooves in workpieces. However, the surface roughness of a narrow borehole can be measured only up to a few millimeters from its end when using a small stylus. Alternatively, destructive measurements must be performed. We previously proposed a novel surface roughness measurement sensor. To make the sensor sufficiently small, we used a stylus with a cylindrical mirror and a lensed fiber instead of a conventional inductive pick-up. The proposed sensor converts the signal used for measuring the surface roughness of a borehole into an optical signal, which is transferred outside the borehole by an optical fiber. The experimental results demonstrate that this system has a measurement range of 8 μm and a sensitivity of 19 nm. In this paper, we propose a carriage that supports the stylus when measuring the surface roughness in a small borehole. The proposed carriage has two degrees of freedom: displacement along the borehole axis and rotation around the borehole axis. In experiments, the surface roughness of standard test pieces was measured using the proposed method and the conventional method. The measurement results obtained by these methods were found to be very similar. Furthermore, a borehole with 2.4 mm diameter was measured. The measurement result included the characteristic wave that was obtained by the conventional method in places. The experiments also revealed some problems of the proposed system. For example, the setting procedure of the measured surface in the 8 μm measurement range was difficult. Consequently, a large measurement range or a null method is required.
Drilling rig sticking, which poses great danger for operators in coal mine production, occurs frequently owing to various factors during the process of drilling in underground coal mines. To solve the sticking problem, the hydraulic power of the drilling rig, which has a significant influence on sticking, is studied. The relation between the torque provided by the hydraulic power unit and the torque required is determined. A model of the hydraulic system based on the multi-way valve applied in a typical drilling rig is built using the hydraulic component design of AMESim; then, the hydraulic system model is simulated under similar working condition with actual condition. Subsequently, a theoretical expression is deduced according to hydraulic and mechanical theorems, and a control method based on dynamic performance curves and relation expression (MDPRE) combining system simulation with theoretical expression is proposed. Finally, experiments are conducted 10 times/shifts to validate the MDPRE. The ultimate results show that the solution is viable and effective.