Traditional pneumatic soft grippers often suffer from a limited contact area and poor shape-matching performance, restricting their effectiveness in handling objects with complex or delicate surfaces. To address this problem, this study proposed an integrated soft gripper that combines pneumatic actuators with specially designed mechanical metamaterials, aiming to optimize deformation characteristics and enhance gripping surface conformity to target objects. The key contributions are as follows: (1) A novel integrated structure is designed, incorporating pneumatic actuators and mechanical metamaterials. (2) A highly efficient design framework based on deep learning is developed, incorporating forward and inverse neural networks to enable efficient performance prediction and inverse design. (3) The novel gripper is fabricated using stereolithography (SLA) and silicone casting, with experimental validation conducted via machine vision and multi-shape object tests. FEA simulations and experiments demonstrate significant improvements in shape matching: average deviations of gripping surfaces from targets are greatly reduced after optimization. This work validates that integrating mechanical metamaterials with data-driven design enhances the gripper’s adaptability, providing a feasible solution for high-performance soft gripping systems.
This study presents an intelligent machine developed for real-time quality monitoring during CNC turning, aimed at improving cutting efficiency and reducing production energy. A dynamometer integrated into the CNC machine captures decomposed cutting forces using the Daubechies wavelet transform. These force ratios are correlated with key workpiece dimensions: surface roughness, average roughness, straightness, and roundness. Two predictive models—nonlinear regression and a feed-forward neural network with Levenberg–Marquardt backpropagation—are employed to estimate these parameters under varying cutting conditions. Experimental results indicate that nonlinear regression models outperform neural networks in predictive accuracy. The proposed system offers effective in-process control of machining quality, contributing to shorter cycle times, lower defect rates, and more sustainable manufacturing practices.
Emin O. Bastekeli, Haci A. Tasdemir, Adil Yucel
et al.
In this study, a novel direct laser beam turning (DLBT) approach is proposed for the precision machining of AISI 308L austenitic stainless steel, which eliminates the need for cutting tools and thereby eradicates tool wear and vibration-induced surface irregularities. A nanosecond-pulsed Nd:YAG fiber laser (λ = 1064 nm, spot size = 0.05 mm) was used, and Ø1.6 mm × 20 mm cylindrical rods were processed under ambient conditions without auxiliary cooling. The experimental framework systematically evaluated the influence of scanning speed, pulse frequency, and the number of laser passes on dimensional accuracy and material removal efficiency. The results indicate that a maximum diameter reduction of 0.271 mm was achieved at a scanning speed of 3200 mm/s and 50 kHz, whereas 0.195 mm was attained at 6400 mm/s and 200 kHz. A robust second-order polynomial correlation (R<sup>2</sup> = 0.99) was established between diameter reduction and the number of passes, revealing the high predictability of the process. Crucially, when the scanning speed was doubled, the effective fluence was halved, considerably influencing the ablation characteristics. Despite the low fluence, evidence of material evaporation at elevated frequencies due to the incubation effect underscores the complex photothermal dynamics governing the process. This work constitutes the first comprehensive quantification of pass-dependent diameter modulation in DLBT and introduces a transformative, noncontact micromachining strategy for hard-to-machine alloys. The demonstrated precision, repeatability, and thermal control position DLBT as a promising candidate for next-generation manufacturing of high-performance miniaturized components.
Monitoring the complete injection molding process is becoming critical for manufacturing high-quality polymer products, as it enhances product quality and process efficiency. This study presents the development of a virtual sensor designed to monitor critical parameters of the injection molding process that cannot be measured with existing sensors. The virtual sensor integrates both one-dimensional system simulations and data-driven models to accurately predict the behavior of the complete injection molding process, including the plasticizing steps. In our investigation, the virtual sensor was tested and demonstrated its ability in forecasting key process parameters, namely the injection pressure and the screw displacement. The sensor’s ability to provide real-time melt temperature or shear rate highlights its practical applicability and effectiveness in optimizing the injection molding process.
Cracks in laser-cladded coatings represent a critical challenge that severely limits their industrial deployment. In this study, high-frequency pulsed direct current-assisted electrically assisted heat treatment (EAHT) was applied to repair cracks in laser-cladded Ni60/WC coatings deposited on 45# medium carbon steel. The influence of current density and treatment duration on crack arrest and healing behavior was systematically investigated. Dye penetrant testing and scanning electron microscopy (SEM) were employed to characterize the morphology and evolution of cracks before and after EAHT, while hardness, fracture toughness, and wear resistance tests were conducted to evaluate the mechanical properties. The results revealed that the crack repair process proceeds through three distinct stages: internal filling, nucleation and growth of healing points, and complete crack closure. The combined effects of Joule heating and current crowding induced by EAHT significantly facilitated progressive crack healing from the bottom upward. Optimal crack arrest and healing were achieved at a current density of 6.25 A/mm<sup>2</sup>, resulting in a maximum fracture toughness of 10.74 MPa·m<sup>1/2</sup> and a transition of the wear mechanism from spalling to abrasive wear. This study demonstrates that EAHT promotes selective crack-tip heating and microstructural regulation through thermo-electro-mechanical coupling, thereby markedly enhancing the comprehensive performance of Ni-based WC coatings.
John Damilola Sunday, Alberto Murillo-Marrodán, Eduardo García
et al.
This study investigates the influence of die design parameters on forging forces and thermomechanical responses during near-solidus forging (NSF) of complex steel components. Finite element simulations using Forge NxT analyzed six die configurations varying geometry orientation, gating system design (conical, cylindrical, curvilinear), and draft angles (20° and 30°), with 42CrMo4E steel modeled at 1360 °C. Key responses including punch and lateral forces, temperature distribution, strain localization, and die stress were evaluated to assess design effects. Results showed that the gating system geometry critically controls material flow and load requirements. The conical gating design with a 30° draft angle yielded the lowest punch (141.54 t) and lateral (149.44 t) forces, alongside uniform temperature and strain distributions, which improve product quality by minimizing defects and incomplete filling. Lower lateral forces also reduce die opening risk, enhancing die life. In contrast, the base case with a 20° draft angle exhibited higher forces and uneven strain, increasing die stress and compromising part quality. These findings highlight the importance of selecting appropriate gating systems and draft angles to reduce forming loads, increase die life, and improve uniform material flow, contributing to better understanding of die design in NSF of complex steel components.
Let $M_{n, m}(\mathbb{R})$ denote the space of $n\times m$ real matrices, and $\mathcal{K}_o^{n,m}$ be the set of convex bodies in $M_{n, m}(\mathbb{R})$ containing the origin. We develop a theory for the $m$th order $p$-affine capacity $C_{p,Q}(\cdot)$ for $p\in[1,n)$ and $Q\in\mathcal{K}_{o}^{1,m}$. Several equivalent definitions for the $m$th order $p$-affine capacity will be provided, and some of its fundamental properties will be proved, including for example, translation invariance and affine invariance. We also establish several inequalities related to the $m$th order $p$-affine capacity, including those comparing to the $p$-variational capacity, the volume, the $m$th order $p$-integral affine surface area, as well as the $L_p$ surface area.
Roll-to-roll (R2R) manufacturing is a continuous processing technology essential for scalable production of thin-film materials and printed electronics, but precise control remains challenging due to subsystem interactions, nonlinearities, and process disturbances. This paper proposes a Model Predictive Path Integral (MPPI) control formulation for R2R systems, leveraging a GPU-based Monte-Carlo sampling approach to efficiently approximate optimal controls online. Crucially, MPPI easily handles non-differentiable cost functions, enabling the incorporation of complex performance criteria relevant to advanced manufacturing processes. A case study is presented that demonstrates that MPPI significantly improves tension regulation performance compared to conventional model predictive control (MPC), highlighting its suitability for real-time control in advanced manufacturing.
Andrey Malakhov, Nemat Niyozbekov, Igor Denisov
et al.
Multilayer composite materials, consisting of layers of aluminum alloy and steel, are used in the manufacturing of large engineering structures, including in the shipbuilding and railcar industries. Due to the different properties of aluminum alloys and steels, it is difficult to achieve high-strength joints by conventional welding. Therefore, these joints are produced by explosive welding. In the present work, the structure of a multilayer material, AA1070-AlMg6-AA1070 (aluminum alloys)-VT1-0-08Cr18Ni10Ti (steel), was investigated after explosive welding and heat treatments were performed under different conditions. The microstructure of the AlMg6 layer at the AlMg6-AA1070 interface consists of shaped anisotropic grains extending along the weld interface. The AA1070 layer is enriched with magnesium due to its diffusive influx from AlMg6. In the AlMg6 and VT1-0 layers, adiabatic shear bands are found that start at the weld interface and propagate deep into the material. The optimal temperature for the heat treatment is 450–500 °C, as internal stresses are reduced at this temperature and the grain structure of the AlMg6 layer is not coarse. Tear strength testing revealed that the tear strength of the composite material after explosive welding was 130 ± 10 MPa, which exceeded the strength of the AA1070 alloy.
The capacity limits of continuous-aperture array (CAPA)-based wireless communications are characterized. To this end, an analytically tractable transmission framework is established for both uplink and downlink CAPA systems. Based on this framework, closed-form expressions for the single-user channel capacity are derived. The results are further extended to a multiuser case by characterizing the capacity limits of a two-user channel and proposing the associated capacity-achieving decoding and encoding schemes. In the uplink case, the capacity-achieving detectors and sum-rate capacity are derived, and the capacity region is characterized. In the downlink case, the uplink-downlink duality is established by deriving the uplink-to-downlink and downlink-to-uplink transformations under the same power constraint, based on which the optimal source current distributions and the achieved sum-rate capacity and capacity region are characterized. For comparison, the uplink and downlink sum-rates achieved by the linear zero-forcing scheme are also analyzed. To gain further insights, several case studies are presented by specializing the derived results into various array structures, including the planar CAPA, linear CAPA, and planar spatially discrete array (SPDA). Numerical results are provided to reveal that the channel capacity achieved by CAPAs converges towards a finite upper bound as the aperture size increases; and CAPAs offer superior capacity over the conventional SPDAs.
This paper studies the capacity of the quantum switch for two decoherence models: when link-level entanglements last (i) for a time slot, or (ii) until they are used to serve a request (i.e., there is no decoherence). The two models are important as they set lower and upper bounds on the capacity region for any other decoherence model. The paper's contributions are to characterize the switch capacity region for both decoherence models and to propose throughput-optimal policies based on gradient descent.
Na busca da qualidade e melhoria contínua, muitas organizações buscam certificar seus sistemas de gestão conforme a ABNT NBR ISO 9001:2015. No entanto, essa norma não faz prescrições sobre como os requisitos podem ser atingidos, o que implica em potenciais desperdícios na implantação. Assim, este estudo teve por objetivo propor um framework para implantação da norma ABNT NBR ISO 9001:2015, integrando princípios e práticas do Lean Six Sigma. A pesquisa foi subdividida em quatro etapas, onde inicialmente buscou-se explorar a literatura sobre o tema. Após, um levantamento das principais ferramentas Lean Six Sigma foi realizado, para então proceder-se com o cruzamento das ferramentas com os requisitos da norma. Por fim, a proposta foi apresentada e validada por um grupo de especialistas. Espera-se, como resultado, auxiliar gestores e tomadores de decisão a implantar a norma ISO 9001de maneira efetiva e eficaz, direcionando o trabalho a ser feito e reduzindo os desperdícios.
Production management. Operations management, Production capacity. Manufacturing capacity
It is a long-standing conjecture that all symplectic capacities which are equal to the Gromov width for ellipsoids coincide on a class of convex domains in $\mathbb{R}^{2n}$. It is known that they coincide for monotone toric domains in all dimensions. In this paper, we study whether requiring a capacity to be equal to the $k^{th}$ Ekeland-Hofer capacity for all ellipsoids can characterize it on a class of domains. We prove that for $k=n=2$, this holds for convex toric domains, but not for all monotone toric domains. We also prove that for $k=n\ge 3$, this does not hold even for convex toric domains.
Miguel Navarro, Amer Matar, Seyid Fehmi Diltemiz
et al.
Due to their unique advantages over traditional manufacturing processes, metal additive manufacturing (AM) technologies have received a great deal of attention over the last few years. Using current powder-bed fusion AM technologies, metal components are very expensive to manufacture, and machines are complex to build and maintain. Wire arc additive manufacturing (WAAM) is a new method of producing metallic components with high efficiency at an affordable cost, which combines welding and 3D printing. In this work, gas tungsten arc welding (GTAW) is incorporated into a gantry system to create a new metal additive manufacturing platform. Design and build of a simple, affordable, and effective WAAM system is explained and the most frequently seen problems are discussed with their suggested solutions. Effect of process parameters on the quality of two additively manufactured alloys including plain carbon steel and Inconel 718 were studied. System design and troubleshooting for the wire arc AM system is presented and discussed.
Berend Denkena, Alexander Krödel-Worbes, Sascha Beblein
et al.
One of the decisive factors for the performance of milling tools is the quality of the cutting edge. The latter results from the process control of the individual steps along the tool manufacturing process chain, which generally includes the sintering or pressing of the blanks, grinding, cutting edge preparation, and coating of the tools. However, the targeted and application-specific design of the process steps in terms of high economic efficiency is currently limited by a lack of knowledge regarding the influence of the corresponding process parameters on the resulting cutting edge quality. In addition, there is a lack of suitable parameters that adequately represent the characteristics of the cutting edge microtopography. This publication therefore investigates the influence of manufacturing processes on cutting edge quality and wear behavior of end mills. On this basis, different characterization parameters for the cutting edge quality are derived and evaluated with regard to their ability to predict the wear behavior.
Herman Budi Harja, Aditya Riyanto Putra, Wibawa Kresnandi
Mesin shot blasting merupakan mesin pembersih produk hasil pengecoran dengan mekanisme shoting bola baja dari gaya sentrifugal yang dihasilkan putaran impeller/blast wheel. Sebagai mesin utama dalam proses akhir kegiatan produksi pengecoran, penurunan kehandalan mesin sangat berdampak negatif pada sistem produksi. Saat ini strategi perawatan peralatan produksi di PT ABC masih menerapkan corrective maintenance yang pelaksanaan perawatnnya tidak terencana dan bersifat reaktif saat kegagalan fungsi mesin terjadi. Hal ini mengakibatkan tingginya production loss dan biaya perawatan meningkat. Oleh karena itu strategi perawatan pada mesin shot blasting diubah menjadi jenis perawatan pencegahan (preventive maintenance). Kajian ini bertujuan untuk merencanakan sistem preventive maintenance (PM) mesin-mesin shot blasting PT. ABC berupa pembuatan jadwal PM, perhitungan waktu downtime dan kebutuhan teknisi pada setiap kegiatan PM_nya. Perencanaan sistem PM dicapai menggunakan metode ISMO (Inspection, Small repair, Medium repair dan Overhaul) dan dilakukan dalam beberapa tahapan yaitu identifikasi obyek mesin, membuat spesifikasi kerja PM, menentukan nilai kerumitan dan siklus pemeliharaan, perhitungan tenaga kerja dan waktu downtime mesin, membuat jadwal tahunan dan bulanan, serta beberapa dokumen perawatan lainnya. Mekanisme penentuan nilai kerumitan, ditentukan berdasarkan kemiripan spesifikasi mesin yang terdapat pada metodologi HP Garg. Perencanaan sistem PM mesin shot blasting telah berhasil dilakukan, beberapa informasi PM yang diperoleh yaitu (i)siklus perawatan mesin adalah C - I1 - I2 - S1 - I3 - I4 - M1 - I5 - I6 - S2 - I7 - I8 - M2 - I9 - I10 - S3 - I11 - I12 – C, (ii) interval waktu antar kegiatan perawatan sebesar 1 bulan, (iii) waktu downtime kegiatan ISMO untuk mesin drum shot, batch shot dan hanger shot, (iv) jumlah dan level teknisi perawatan yang dibutuhkan pada setiap kegiatan ISMO untuk mesin drum shot, batch shot dan hanger shot. Verifikasi perhitungan nilai availability mesin shot blasting pada usulan jadwal PM diperoleh bahwa availability mesin meningkat menjadi lebih dari 80%.
Abdur Rohman Harits Martawireja, Hilman Mujahid Purnama, Atika Nur Rahmawati
Pengenalan wajah manusia (face recognition) merupakan salah satu bidang penelitian yang penting dan belakangan ini banyak aplikasi yang menerapkannya, baik di bidang komersil ataupun di bidang penegakan hukum. Pengenalan wajah merupakan sebuah sistem yang berfungsikan untuk mengidentifikasi berdasarkan ciri-ciri dari wajah seseorang berbasis biometrik yang memiliki keakuratan tinggi. Pengenalan wajah dapat diterapkan pada sistem keamanan. Banyak metode yang dapat digunakan dalam aplikasi pengenalan wajah untuk keamanan sistem, namun pada artikel ini akan membahas tentang dua metode yaitu Two Dimensial Principal Component Analysis dan Kernel Fisher Discriminant Analysis dengan metode klasifikasi menggunakan K-Nearest Neigbor. Kedua metode ini diuji menggunakan metode cross validation. Hasil dari penelitian terdahulu terbukti bahwa sistem pengenalan wajah metode Two Dimensial Principal Component Analysis dengan 5-folds cross validation menghasilkan akurasi sebesar 88,73%, sedangkan dengan 2-folds validation akurasi yang dihasilkan sebesar 89,25%. Dan pengujian metode Kernel Fisher Discriminant dengan 2-folds cross validation menghasilkan akurasi rata rata sebesar 83,10%.
The objective of the paper is to analyze the cooperation in craft beer manufacturing in Poland and to identify the specificity of this phenomenon from the perspective of enterprise management. The sales of craft beers in Poland are growing rapidly. Craft beers have about a 0.5% share in the total beer sales value in Poland. The popular practice in the industry is contract brewing. It is an interesting phenomenon in the field of cooperation of enterprises which can be classified and analyzed as a form of: economic cooperation (generally), production cooperation, outsourcing, network and virtual organization and also coopetition. It is a specific business model. Contract brewing is a complex problem the specificity of which emerges on several levels. Firstly, there is a special way to emerge in the market of craft beers, even while not possessing significant funds by the entrepreneur. Secondly, it is a form of cooperation in the field of production which unites efforts on the side of both the customer and the contractor since it is not limited to normal outsourcing of production to an external entity but involves physical production capacity of the contractor and technological know-how of both cooperation parties. Thirdly, it is firmly embedded in human relationships. Fourthly, it can generate coopetitive relations since the brewery accepting the order may conduct its own activity related to production and sales of beer under its own brand.
Machine design and drawing, Engineering machinery, tools, and implements