International Journal of Mechatronics and Manufacturing Systems (10 papers in press)
Hardware and Software Complex and a Device for Setting Optimal Parameters of the Unit Injector Operation in Diesel Engines
by Ildar Gabitov, Samat Insafuddinov, Nail Yunusbaev, Timur Farhutdinov, Albert Sharafeev, Farid Abdrazakov, Filyus Safin, Elmir Gaysin, Ural Makhiyanov
Abstract: The purpose of this study is to develop a device for setting optimal parameters of a unit injector operation in diesel engines and to justify its design. The other goal is to create a hardware and software complex with a function of modernizing the adjustment rigs. The study analyzes factors that affect the law of fuel supply in the unit injectors. Findings from this analysis base the calculation methods and the regulation parameters of unit injectors. The adjustment parameters of the fuel supply system (cyclic design in particular) are calculated with regard to the injection chamber pressure using a the suggested hardware and software complex.
Keywords: fuel system; unit injector; diesel engine; injection; indication; gas pressure; compression; expansion; simulation of injection.
Automatic Alignment and Location of Multiple Fiducial Marks
by Chuen-Horng Lin, Chih-Chin Wen, Jr-Wei Chen
Abstract: This paper proposes a method for the automatic alignment of reference fiducial marks (RFM) on light-emitting diode (LED) wafer images, and for locating the position of RFMs on LED wafer images, liquid crystal display (LCD) images, hand-held electronic device (HED) images, LCD cross images and LED square cross images.
This paper proposes methods for the alignment and location of fiducial marks (FM) on two types of FM images. FM images of the first type include LED wafer images, LCD images and HED images. Among these, in this paper, FMs are identified by alignment using RFM. FM images of the second type include LCD cross images and LED square cross images. For these images, the cross points and angles between lines are captured by alignment. In addition, this paper proposes the artificial measurement method (ArtTMM) and the mechanical measurement method (MeaMM) in order to make mechanical positioning-related decisions. To validate the properties and the robustness of the proposed methods, MeaMM is used for the HED image, and ArtMM is used for other images.
The automatic RFM alignment method for the LED wafer images achieves effective alignment of FMs on the upper layer, while FMs on lower layers enable simple RFM user selection. RFMs on the LCD and HED images are selected by artificial means. The results achieved by the proposed matching, alignment methods are compared with those achieved by manual image matching in order to evaluate the accuracy and performance of the alignment methods. Computer image processing skills, appropriate CCD equipment, quantity, image capture technology, and glazing mode are used to develop high speed, high precision, and high stability automatic positioning technology in this paper.
Keywords: fiducial mark; reference fiducial marks; automatic detection; automatic location.
A cost-effective device for on-line measurement of sheet metal bending angle on cnc press brakes based on capacitive sensors
by G.-C. Vosniakos, Stefanos Raftopoulos
Abstract: Sheet metal bending on press brakes is one of the most widespread manufacturing processes. A common issue in press brake bending is the deviation of the actual bending angle from the theoretical one due to elastic spring-back of the sheet metal. This is typically rectified by a systematic trial-and-error process, which has to be based on a suitable measuring device that is flexible enough to adapt to a wide range of computer numerically controlled machines, accurate enough with respect to modern manufacturing needs and cost effective enough to be used on low cost press brakes. This work presents the development of such a device resembling a miniature robotic arm and employing capacitive sensors. Two stepping motors adapt the arm to any bending angle sheet configuration. The measuring process is commanded by a microcontroller. Statistical evidence on accuracy and repeatability of the system is provided, being better than 0.1? and 0.3? whilst cost is kept reasonable.
Keywords: press brake; elastic springback; measurement; capacitive sensors; microcontroller; bending angle.
Machine vision support of VARI process automation in composite part manufacturing
by Stefanos Lekanidis, G.-C. Vosniakos
Abstract: This paper presents a system for monitoring and regulating the injection of resin into technical fabric pieces laid up against a die, a process that is commonly used in the production of composite materials by vacuum (VARI). To implement this system, a conventional webcam was used to capture the flow of resin and standard machine vision routines were put together to construct a suitable environment to detect the resin flow front. In addition, a sample hydraulic/pneumatic system for infusing the resin was designed and implemented, consisting of inlet and outlet valves. A suitable electronic circuit was designed to control the hydraulic/pneumatic system and control code was developed using a low cost microcontroller. A typical example is presented based on which the general systems concept is explained and discussed.
Keywords: machine vision; monitoring; control; resin infusion; composites; Vacuum Assisted Resin Infusion; valves.
Design and optimization of a turning cutter embedded with impact damper
by Donghui Wu, Xi Wang, Yiqing Yang
Abstract: The cutter with large length-diameter ratio has wide applications in machining structural parts with deep cavity and deep hole features. However, the dynamic stiffness of the cutter declines as the length-diameter ratio increases, which causes chatter vibration during the machining process. The impact damper has been utilized to suppress machining vibration due to its simplicity and effectivity. A turning cutter with large length-diameter ratio is designed based on embedded impact damper. The dynamic model is built based on mode superposition method. The influence of cutting force and damping parameters on velocity response status (linear and nonlinear) is analyzed. Design parameters of the impact damper are optimized numerically for achieving linear response. Finally, modal tests and machining tests are conducted. The experimental results show that the surface roughness of workpiece (aluminum alloy 7075) is decreased from Ra 1.95 ?m to Ra 1.28 ?m when the spindle speed n=500 r/min, feed rate f=0.05 mm/r and cutting depth ap=0.40 mm.
Keywords: turning; cutter; impact damper; linear response.
Planning and control frameworks of the future
by Johannes Cornelis De Man, Jo Wessel Strandhagen, Sven-Vegard Buer, Jan Ola Strandhagen
Abstract: Since the 1970s, multiple planning and control frameworks have been introduced. The current digitalization of the manufacturing industry, with all its Industry 4.0 related technologies, will have major implications on manufacturing logistics, and may change how manufacturing companies plan and control their production. In this paper, we discuss the effects of the developments in planning frameworks and technologies on different factors that constitute planning and control. These are the balance between human and automated planning, the influence on mid-term planning due to improved forecast accuracy, the influence of real-time information on short-term planning, horizontal and vertical integration and the impact on supply chain performance. The application of new technologies will lead to changes in all of these factors that cannot be fully captured by current planning and control frameworks. These factors need to be integrated into future frameworks in order to structure future research into planning and control.
Keywords: planning and control; planning frameworks; Industry 4.0; technology application.
Performance of PVD and CVD coated cutting tool inserts in machining under MQL-MQSL environment
by Mayurkumar Makhesana, Kaushik Patel
Abstract: The current study evaluated the performance of coated tools during machining of AISI 52100 and addressed the applicability of minimum quantity lubrication (MQL) and minimum quantity solid lubrication (MQSL). Experimental investigations have been done to evaluate the machinability aspects such as flank wear and hence tool life, forms of tool wear and surface roughness in turning of AISI 52100 steel using dry, MQL and MQSL machining with PVD multilayer (TiAlN/TiN) and CVD bilayer (TiCN/Al2O3) coated carbide inserts. Longer tool life is observed under MQL and MQSL cutting conditions, which can be due to enhanced lubrication and cooling effect. It can be seen that PVD multilayer (TiAlN/TiN) coated carbide tool with MQL and MQSL performed effectively as compared to CVD bilayer (TiCN/Al2O3) tools for selected cutting environments. PVD multilayer (TiAlN/TiN) tool with a better adhesion strength of the coating layer to the substrate resulted in the higher tool life of almost up-to 15-20%. Excellent tribological properties of TiAlN/TiN multilayer coating are observed in the form of an improvement in tool life and surface finish of the workpiece. Based on the findings, the presented approach can be considered as an eco-friendly and cost-effective alternative, which provides a more clear methodology to select the combination of the cutting tool and lubrication strategy.
Keywords: Turning; flank wear; surface roughness; CVD coated tools; PVD coated tools; MQL; MQSL.
EVALUATION ON ADVANTAGES OF LOW FREQUENCY ASSISTED DRILLING (LFAD) ALUMINUM ALLOY Al7075
by Fernando Veiga, Alfredo Suarez, Alain Gil Del Val, Mariluz Penalva, Luis Norberto López De Lacalle
Abstract: Drilling operation of dissimilar stack materials is a crucial assembly operation in airframe manufacturing; this is due to both the number of holes drilled in an aircraft structure and the fact that this is an operation performed in the finishing phase of the manufacturing chain. This article aims to evaluate an alternative strategy for conventional drilling and peck drilling, which are now the most widespread solutions used for drilling aluminium alloys. The alternative approach proposed by this article consists of low frequency assisted drilling (LFAD) performed into frequencies vibrations (between 50 to 100 Hz). In this paper, the chip formation process of drilling assisted by low-frequency vibrations of FC/Al stack material has been analytically modelled and compared with the conventional drilling of aluminium. As it is well known, the geometric quality of drilled holes is crucial for the correct final assembly of the pieces; therefore, the advantages on the quality of the vibration-assisted drilling technique on drilled holes quality have been evaluated. Results show chip segmentation during the drilling operation resulting in less temperature increasing, avoiding problems in the final geometrical quality of the hole, and also burr formation.
Keywords: Vibration assisted drilling; hole quality; chip thickness modelling; burrs.
Ultrasonic vibration-assisted single point incremental forming of hemispherical shape using multi-stage forming strategy
by Ashish Gohil, Bharat Modi, Kaushik Patel
Abstract: Ultrasonic vibrations have found widespread engineering applications. The use of ultrasonic vibrations in machining and welding processes have reached the commercially viable stage. However, the application of ultrasonic vibrations in sheet metal forming applications is still in the research phase. This paper addresses the application of ultrasonic vibrations in a single point incremental forming process. The main focus of the paper is on the development of the ultrasonic vibration-assisted forming set-up customized to the vertical machining center. Experiments have also been conducted with the developed set-up to produce the hemispherical shape which is difficult to form using a single-stage strategy using the single point incremental forming process. A multi-stage forming strategy has been used to form the hemispherical shape and the analysis of the results has been presented.
Keywords: Ultrasonic vibration; SPIF; Converter; Booster; Tool cone; Longitudinal vibration; multi-stage forming; hammering frequency; cumulative depth; step-depth.
Measurement of force and torque in friction stir welding of low carbon steels
by Pardeep Pankaj, Avinish Tiwari, Pankaj Biswas, A. Gourav Rao
Abstract: Nowadays, a challenging issue during the friction stir welding (FSW) of the high strength material like steels is the development of the force & torque measuring dynamometer, which is capable of supporting the higher loads as well as the higher temperatures generated during the welding process. In present work, a strain gauge based dynamometer was designed and developed for monitoring the vertical force, traverse force and torque during FSW of low carbon steels. The 3D finite element (FE) analysis was performed to detect the suitable positions for mounting the strain gauges on the octagonal ring members for different real time loading conditions (i.e., vertical force, traverse force and torque). Analytical methods were used to estimate the mechanical responses i.e., stress, strain, and vibration frequency of the octagonal ring members. When the load was acting on the octagonal members during the welding process, the induced strain in the octagonal members was recorded by the data acquisition system. The data acquisition system was connected to the developed dynamometer with the essential software and hardware to record the strain data automatically on a computer during welding. After completing the construction, the dynamometer was tested by performing the friction stir welding on DH36 shipbuilding steel and mild steel (UNS G10080 steel) plates in similar and dissimilar combinations. The results showed that the developed dynamometer can be suitable for measuring the real time vertical force, traverse force and torque during the FSW of low carbon steels.
Keywords: Friction stir welding; dynamometer; traverse force; vertical force; torque; low carbon steels