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Table of Content

    25 September 2017, Volume 5 Issue 3
    Articles
    Haptic and visual augmented reality interface for programming welding robots
    D. Ni, A. W. W. Yew, S. K. Ong, A. Y. C. Nee
    2017, 5(3):  191-198.  doi:10.1007/s40436-017-0184-7
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    It is a challenging task for operators to program a remote robot for welding manipulation depending only on the visual information from the remote site. This paper proposes an intuitive user interface for programming welding robots remotely using augmented reality (AR) with haptic feedback. The proposed system uses a depth camera to reconstruct the surfaces of workpieces. A haptic input device is used to allow users to define welding paths along these surfaces. An AR user interface is developed to allow users to visualize and adjust the orientation of the welding torch. Compared with the traditional robotic welding path programming methods which rely on prior CAD models or contact between the robot end-effector and the workpiece, this proposed approach allows for fast and intuitive remote robotic welding path programming without prior knowledge of CAD models of the workpieces. The experimental results show that the proposed approach is a user-friendly interface and can assist users in obtaining an accurate welding path.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0184-7

    Experimental study and optimization of cutting parameters in machining of super alloy with hybrid ultrasonic method
    Dipesh Popli, Meenu Gupta
    2017, 5(3):  199-216.  doi:10.1007/s40436-017-0185-6
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    Super alloys are intensively used in various industries, especially in the aerospace industry, because of their special characteristics. A number of holes are sometimes required to be drilled into super alloys for aircraft at their final stage assembly. In the present study, a hybrid ultrasonic machining method, called rotary ultrasonic machining (RUM), was successfully used in super alloy drilling. The empirical modeling of the process parameters of RUM was performed for the super alloy (Inconel 718) using an experimental design approach, called response surface methodology (RSM). Parameters, namely tool rotation, feed rate, ultrasonic power, and abrasive grit size, were selected as input variables. The others were kept constant. The performance was measured in terms of the machining rate and the surface roughness. The developed models were found to be reliable representatives of the experimental results with prediction errors less than ±5%. Moreover, the feed rate for the quality and productivity aspect was found to be the most critical factor. The optimized values of the machining rate and the surface roughness achieved through a multi-response optimization were 0.9 825 mm3/s and 0.951 μm, respectively.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0185-6

    Investigation on surface structuring generated by electrochemical micromachining
    Sandip Kunar, B. Bhattacharyya
    2017, 5(3):  217-230.  doi:10.1007/s40436-017-0186-5
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    Surface geometrical features and their functionality depend on the manufacturing process which is employed for fabrication of surface structures. Maskless electrochemical micromachining (EMM) is used to generate various surface structures for diminishing and controlling friction and wear to increase the lifetime, reliability, and efficiency of mechanical systems. This paper presents a method for the generation of structured surfaces on stainless steel (SS-304) surfaces by using maskless EMM. The micropatterned tool is composed of 800 μm diameter circular holes in a 5×5 matrix form. The indigenously developed EMM set up consists of an EMM cell, electrical power supply system, and a controlled vertical cross-flow electrolyte circulation arrangement to control the influence of process parameters during the generation of the micro features of structured surfaces. The single structured cathode tool is used for the mass production of structured surfaces with a short fabrication time in the industrial context by avoiding the use of an individual masking process for each workpiece. The process has been characterized in terms of the effects of predominant process parameters such as machining voltage, electrolyte concentration, duty ratio, pulsed frequency, and machining time on the machined surface characteristics such as current efficiency, machining accuracy, and depth of the circular pattern on the stainless steel surfaces. A mathematical model is also developed to determine the theoretical depth of the dimple pattern and correlate the theoretical depths with actual depths as obtained by experimentation.Moreover, an effort has been made to study the structuring characteristics on the basis of micrographs obtained during the EMM.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0186-5

    Optimization of fused deposition modeling process parameters using a fuzzy inference system coupled with Taguchi philosophy
    Saroj Kumar Padhi, Ranjeet Kumar Sahu, S. S. Mahapatra, Harish Chandra Das, Anoop Kumar Sood, Brundaban Patro, A. K. Mondal
    2017, 5(3):  231-242.  doi:10.1007/s40436-017-0187-4
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    Fused deposition modeling (FDM) is an additive manufacturing technique used to fabricate intricate parts in 3D, within the shortest possible time without using tools, dies, fixtures, or human intervention. This article empirically reports the effects of the process parameters, i.e., the layer thickness, raster angle, raster width, air gap, part orientation, and their interactions on the accuracy of the length, width, and thickness, of acrylonitrile-butadienestyrene (ABSP 400) parts fabricated using the FDM technique. It was found that contraction prevailed along the direction of the length and width, whereas the thickness increased from the desired value of the fabricated part. Optimum parameter settings to minimize the responses, such as the change in length, width, and thickness of the test specimen, have been determined using Taguchi's parameter design. Because Taguchi's philosophy fails to obtain uniform optimal factor settings for each response, in this study, a fuzzy inference system combined with the Taguchi philosophy has been adopted to generate a single response from three responses, to reach the specific target values with the overall optimum factor level settings. Further, Taguchi and artificial neural network predictive models are also presented in this study for an accuracy evaluation within the dimensions of the FDM fabricated parts, subjected to various operating conditions. The predicted values obtained from both models are in good agreement with the values from the experiment data, with mean absolute percentage errors of 3.16 and 0.15, respectively. Finally, the confirmatory test results showed an improvement in the multi-response performance index of 0.454 when using the optimal FDM parameters over the initial values.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0187-4

    A brief overview on secure control of networked systems
    Hong-Tao Sun, Chen Peng, Peng Zhou, Zhi-Wen Wang
    2017, 5(3):  243-250.  doi:10.1007/s40436-017-0189-2
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    This paper focuses on the issues of the security of networked control systems by summarizing recent progress in secure control of this research and application area. We mainly discuss existing results, especially in modeling issues, of three aspects:(1) attack mechanisms and their impacts on control systems, (2) the identification and design of attacks, and (3) secure estimation and control strategies. A conclusion is drawn at the end of this paper. In addition, several promising research tendencies of the development for secure control in networked control system are presented.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0187-4

    Surface texture formation in precision machining of direct laser deposited tungsten carbide
    Szymon Wojciechowski, Zbigniew Nowakowski, Radomir Majchrowski, Grzegorz Królczyk
    2017, 5(3):  251-260.  doi:10.1007/s40436-017-0188-3
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    This paper focuses on an analysis of the surface texture formed during precision machining of tungsten carbide. The work material was fabricated using direct laser deposition (DLD) technology. The experiment included precision milling of tungsten carbide samples with a monolithic torus cubic boron nitride tool and grinding with diamond and alumina cup wheels. An optical surface profiler was applied to the measurements of surface textures and roughness profiles. In addition, the micro-geometry of the milling cutter was measured with the application of an optical device. The surface roughness height was also estimated with the application of a model, which included kinematic-geometric parameters and minimum uncut chip thickness. The research revealed the occurrence of micro-grooves on the machined surface. The surface roughness height calculated on the basis of the traditional kinematic-geometric model was incompatible with the measurements. However, better agreement between the theoretical and experimental values was observed for the minimum uncut chip thickness model.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0188-3

    Recognition results classification and post-processing methods for painted characters on billet surface
    Qi-Jie Zhao, Chun-Hui Huang, Zhen-Nan Ke, Jin-Gang Yi
    2017, 5(3):  261-270.  doi:10.1007/s40436-017-0190-9
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    Automatic identification of characters marked on billets is very important for steelworks to achieve manufacturing and logistics informatization management. Due to the presence of adhesions, fractures, blurs, and other problems in characters painted on billets, character recognition accuracy with machine vision is relatively low, and hardly meets practical application requirements. To make the character recognition results more reliable and accurate, an identification results classification and post-processing method has been proposed in this paper. By analyzing issues in the image segmentation and recognition stage, the recognition result classification model, based on character encoding rules and recognition confidence, is built, and the character recognition results can be classified as correct, suspect, or wrong. In the post-processing stage, a human-machine-cooperation mechanism with a postprocessing interface is designed to eliminate error information in suspect and wrong types. The system was developed and experiments conducted with images acquired in an iron and steel factory. The results show the character recognition accuracy to be approximately 89% using the character recognizer. However, this result cannot be directly applied in information management systems. With the proposed post-processing method, a human worker will query the suspect and wrong results classified by the system, determine whether the result is correct or wrong, and then, correct the wrong result through the post processing interface. Using this method, the character recognition accuracy ultimately improves to 99.4%. Thus, the results will be more reliable applied in a practical system.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0190-9

    Effect of flow control mold on flow field during high-speed continuous casting
    Zhan Yu, Zheng-Qiang Zhang, Zhong-Ming Ren
    2017, 5(3):  271-278.  doi:10.1007/s40436-017-0183-8
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    An experimental mold was built to study the flow in a flow control mold under high speed continuous casting. The effect of the magnetic field on the flow was investigated using mercury. The results show that the magnetic field can not only dampen the flow of liquid metal but also change its direction, and then redistribute the flow in the mold. When maintaining a constant distance between magnets, the fluctuation of the free surface is dampened because of the increasing magnetic flux density. The flow at the free surface is improved, and the penetration depth of the downward stream is reduced. The decrease in the distance between magnets promotes the brake effect and the flow is dampened in the upper eddy.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0183-8

    Optimization of rollover stability for a three-wheeler vehicle
    S. A. Sree Ram, P. Raja, K. Sreedaran
    2017, 5(3):  279-288.  doi:10.1007/s40436-017-0191-8
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    An auto rickshaw is a three-wheeled motor vehicle commonly found in Asia, with one front steering wheel and two driven wheels at the back. In automobiles, suspension is used to keep the wheels planted during motion. The trailing arm suspension generally found in Indian automobiles has its roll center on the ground. The vehicle's center of gravity is above the ground, which creates a moment during vehicle turning known as the roll moment. When this roll moment exceeds a certain limit, the vehicle becomes unstable. Roll rate can be expressed as degrees per lateral acceleration of the vehicle's sprung mass, and is influenced by factors such as wheel rate, motion ratio, and suspension rate. In order to determine an optimized three-wheeler suspension setup, a matrix selection method was used, in which every available suspension type in the market is rated based on selected suspension parameters such as handling, dynamics, and simplicity. From the overall weightage, each suspension type is analyzed and the most appropriate is selected. In order to achieve the objective of improving the overall rollover stability, certain modifications have been applied in the selected suspension design. Generally, if the roll rate of a specific vehicle axle is high, the percentage of weight transfer on the axle will also be high. By improving roll stiffness, the amount of roll can be decreased, and by optimizing the motion ratio, the roll moment can be controlled, thereby increasing the overall rollover stability.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0191-8

    Hydrogenation of graphene nanoflakes and C-H bond dissociation of hydrogenated graphene nanoflakes:a density functional theory study
    Sheng Tao, Hui-Ting Liu, Liu-Ming Yan, Bao-Hua Yue, Ai-Jun Li
    2017, 5(3):  289-298.  doi:10.1007/s40436-017-0180-y
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    The Gibbs free energy change for the hydrogenation of graphene nanoflakes Cn (n=24, 28, 30 and 32) and the C-H bond dissociation energy of hydrogenated graphene nanoflakes CnHm (n=24, 28, 30 and 32; and m=1, 2 and 3) are evaluated using density functional theory calculations. It is concluded that the graphene nanoflakes and hydrogenated graphene nanoflakes accept the ortharyne structure with peripheral carbon atoms bonded via the most triple bonds and leaving the least unpaired dangling electrons. Five-membered rings are formed at the deep bay sites attributing to the stabilization effect from the pairing of dangling electrons. The hydrogenation reactions which eliminate one unpaired dangling electron and thus decrease the overall multiplicity of the graphene nanoflakes or hydrogenated graphene nanoflakes are spontaneous with negative or near zero Gibbs free energy change. And the resulting C-H bonds are stable with bond dissociation energy in the same range as those of aromatic compounds. The other C-H bonds are not as stable attributing to the excessive unpaired dangling electrons being filled into the C-H anti-bond orbital.

    The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0180-y