The first contribution in this section of the book presents a vision for the future of the machine tool industry in the form of a LEG2O machine tool system. One of the most important limiting factors for machining quality at high cutting speeds is the static and dynamic behavior of a machine tool (Ast et al. 2007). In the machine tool sector, retrofitting is a common principle in the quest to revive obsolete machine tools.
Dry Machining
In the final step, the upgrade of the machine tools can be done as needed. By upgrading or improving the functionality of outdated machine tools rather than replacing them with new machines, valuable resources can be saved (Allwood et al. 2011).
Smart Building Block Systems
In the context of sustainable design, resource efficiency was set as a goal during the design phase of the passive module. Figure 3 shows the development history of the different design phases of passive modules and shows the topologically optimized hexagons with a weight of 6.2 and 12.3 kg, respectively. Module identification data and parameters related to the physical condition of the machine tool frame are shared between smart modules and one centralized receiving unit using wireless communication.
The control loop of the actuators uses online data, transmitted wirelessly by smart modules. At a simplified level, the construction and applicability of this approach, as well as the associated sustainability benefits and control of the active module, were analyzed (Uhlmann and Peukert 2015). Figure 5 shows the actuator and experimental results of the closed loop control in a prototypical test structure.
A combined hardware and software infrastructure synchronizes all relevant data for the analysis of thermal deformation of the frame, as shown in Figure 6. 4 wireless sensor nodes for parameter monitoring of passive LEG2O modules – the latest technology demonstrator of the sensor fits into a hollow M18 -screw.
Add-Ons for Machine Tool Upgrade
Sensors of the attachment system can measure a significant part of the static, dynamic and kinematic inaccuracies. The added error compensation table is managed by separate control hardware (dSPACE 1103) and does not share the machine tool control unit, making the solution developed both modular and independent of the machine type. These capabilities are achieved through independent control, as only one interface to the machine tool is required for sensor readings, together with a screw connection from the table, see also (Kianinejad et al.2016).
A capacitive sensor mounted in the frame is used in each direction to detect the movement of the platform relative to the frame. In addition to measuring the quasi-static position, these sensors also measure the dynamic movement of the platform. A lookup table is generated containing the repeatable error of initial measurements on the machine's linear positioning in the x and y axes.
By feeding the lookup table with the reference position (x, y) of the linear encoders from FP4NC, FRIEDRICH DECKEL AG, Munich, Germany, a reference signal is generated. This reference signal is then fed to the xy table control for tracking.
Internally-Cooled Tools
However, due to the influence of the coolant temperature, the TCP shows a shift of up to dT = 0.2 mm. In this process, the actuator of the various actuation principles as well as the optimal placement within the machine tool frame serve together to improve energy efficiency and combine the advantages of the principles. Although modularization was achieved on the hardware side of the machine tool among the various components, the net effect on the durability of the machine tool frame modularization remains an open question.
Sensors of the attachment system can measure some of the static, dynamic and kinematic inaccuracies. Identification and control of dynamical systems using neural networks.IEEE Transactions on Neural Networks/A Publication of the IEEE Neural Networks Council1(1): 4–27. Minimization of residual vibrations of ultra-precise production machines through optimal placement of vibration isolators. Precision engineering.
Investigating the upgrading potential of obsolete cutting machine tools to promote sustainable and global value creation. Meanwhile, GMAW is one of the most widely used technologies due to the fact that it is easy to automate and offers a high level of productivity and flexibility. To evaluate the environmental impacts and social influences of a process or product, Life Cycle Assessment (LCA) (ISO 2006a; Schau et al. 2012), and Social Life Cycle Assessment (SLCA) (UNEP 2009) are the current state of the art.
To that end, MMAW, LAHW and automatic GMAW with a conventional spray arc and a modified spray arc have been evaluated in the light of the environmental and social aspects.
Environmental Assessment
Furthermore, the wage status of welders in Germany has been examined with a discussion of fairness and adequacy considering their working and living conditions. In the life cycle inventory analysis phase, inventory data is collected for the inputs and outputs of the selected welding processes according to the system boundary and the functional unit. The electricity consumption for the welding processes was determined with measured values and the respective wall plug efficiency of the equipment.
For LAHW, the beam source electricity consumption took into account process power, an efficiency of 30% and additional contributions from the cooling unit. The electrical energy to move the robot was measured on the power cable for the respective trajectories and added to the electrical energy demand of the welding source to calculate the total energy used for the joining process. Filler consumption was determined by measuring the wire feed rate and, in the case of MMAW, by weighing the electrodes and collecting the remaining electrode scraps.
For MMAW, only titanium dioxide (45%) and silicon dioxide (10%) were considered to represent the main composition of the electrode coating due to missing data in the GaBi database. The consumption of compressed air for LAHW was estimated by applying Bernoulli's principle to the geometry of the laser head cross beam unit.
Social Assessment
Smoke emissions are calculated according to the emission rate of representative processes (power range and transfer mode) from the literature (Pohlmann et al. 2013;. The chemical composition is assumed to be mainly iron oxide (Antonini et al. 2006; Jenkins and Eagar 2005 Then there is POCP (in kg ethene equivalent), which estimates the creation of ozone (due to the reaction of a substance in the presence of NOx gases), also known as summer smog (Guinée et al.2002).
Welding processes generate a complex mixture of fumes (respirable and ultrafine particles) as by-products consisting of a range of metals volatilized from the welding electrode or the flux material incorporated (Antonini et al. 2006). Iron oxides make up the main part of the vapor, while chromium, manganese and nickel make up the total residual vapor composition (Antonini et al.2006; Jenkins and Eagar2005). To represent the relative potential risk caused by fumes to the health of welders, we have identified the hazard rate (Gefährdungszahl, GZ) of the welding processes.
Erepresents smoke emissions per functional unit of 1 m of weld and is calculated based on data from the LCA smoke emission record (see section 2.1). According to Equation 1 and the assumptions on the potential health risk, GZs, the functional unit emission factor E and the relative head/body distance and smoke source Kb are strongly influenced.
Welding Experiments
Also, both lands are set as 1 on paper due to the condition of the solder places which are supposed to be identical. The material specification, groove preparations and process parameters of the processes are listed in Tables 2 and 3. The LCA study highlights the environmental impacts contributed by the various inputs and outputs of the selected welding processes and compares the differences in environmental impacts.
In addition, LAHW allows high welding speeds, leading to high productivity and low electricity and gas Table 4 Life cycle inventory of welding processes. Both can be optimized by increasing the width of the root face and a smaller opening angle. Furthermore, electrode wear constitutes a significant part of the environmental impact even though only 55% of the electrode composition is considered in the LCA model.
Filler consumption dominates approximately 54–80 % of the cases of impact in GMAW in the selected categories. Nevertheless, gaps and limitations of the study must be acknowledged, for example the challenges embedded in LCA methodology (Finkbeiner et al.2014) and the possible variation of results due to different process requirements in welding technology.
Social Assessment
It provides information to both industry and the research community for developing and selecting interconnection technologies for the triple bottom line of sustainability. Occupational health and safety regulations relating to welding and assessment of exposure to welding fumes and its consequences. Welding and cutting11 (1). Analysis of the approaches shows that effective solutions require both earmarked funding and qualified personnel, both of which are unaffordable for many companies.
This chapter demonstrates this process using the example of a "Working Posture Controller" (WPC) to illustrate how the HCA concept can be applied. In terms of economic sustainability, the direct costs of unfavorable working conditions reduce a country's gross domestic product (GDP) (Bevan 2015), which is considered one of the main indicators of economic sustainability defined by the United Nations Department of Economic Affairs. and Social Affairs (2007). Musculoskeletal diseases (bone-muscle diseases) pose a serious threat to the health and thus the sustainability of the workforce.
The European Agency for Safety and Health at Work (Schneider et al.2010) defines MSDs as "health problems of the musculoskeletal system, which include muscles, tendons, the skeleton, cartilage, the vascular system, ligaments and nerves." Work-related or Occupational Musculoskeletal Disorders (WMSDs) include all MSDs caused or exacerbated by work. The total cost of WMSDs is estimated at 240 € billion, which amounts to up to 2 % of EU GDP (Bevan2015).
