focalinterest.net

Tag: Manufacturing & Industrial Engineering

  • Online genetic programming improved flexible job shop scheduling

    What the study found

    The study found that an online genetic programming (OGP) framework can learn scheduling strategies directly in the operating environment. In tests on dynamic flexible job shop scheduling problems, the authors report that it outperformed existing scheduling algorithms when scheduling and routing decisions were considered together.

    Why the authors say this matters

    The authors say this matters because existing genetic programming approaches depend on simulation models, extensive data, and limited adaptability to changing conditions. The study suggests OGP may be a more robust and generalisable optimisation framework for dynamic decision-making in changing environments.

    What the researchers tested

    The researchers developed the first online genetic programming framework that learns without prior knowledge or an explicit simulation model. They tested it on dynamic flexible job shop scheduling problems, using an adaptive fitness function, a phenotypic archive for predictive evaluation, a pre-selection strategy to control rule complexity, and a soft restart mechanism to maintain diversity.

    What worked and what didn't

    According to the abstract, OGP outperformed existing scheduling algorithms on the tested dynamic flexible job shop scheduling problems when both scheduling and routing were optimized together. The proposed method also generated competitive rules compared with state-of-the-art genetic programming methods in test performance and rule size. The abstract does not report which specific conditions it performed poorly under, if any.

    What to keep in mind

    The summary is limited to the abstract, so detailed experimental settings and numerical results are not provided here. The tests were conducted on dynamic flexible job shop scheduling problems, so the reported findings are scoped to that type of scheduling environment.

    • The study reports a first online genetic programming framework for learning scheduling strategies directly in the operating environment.
    • Dynamic flexible job shop scheduling problems were used as the test setting.
    • The abstract says the method outperformed existing scheduling algorithms when scheduling and routing decisions were both considered.
    • The proposed method produced competitive rules compared with state-of-the-art genetic programming methods in test performance and rule size.
    • The abstract does not describe any specific limitations or failure cases.

  • Dynamic steering control improved robot path tracking outdoors

    What the study found

    The study found that Pure Pursuit with Dynamic Steering Control (PP-DSC) improved trajectory tracking for an autonomous mobile robot in open outdoor tests. It also found that adding a Fire and Explosion Index (F&EI)-based safety factor helped automate speed reduction in hazard zones, but industrial use depended on the site geometry.

    Why the authors say this matters

    The authors conclude that the method can improve trajectory tracking in open-field environments. They also suggest the safety-integrated version may support Process Safety Management (PSM), meaning organized management of process hazards, by reducing velocity in hazardous areas.

    What the researchers tested

    The researchers proposed PP-DSC, which adaptively adjusts lookahead distance and velocity based on steering angle. They deployed it on a four-wheeled steering-type autonomous mobile robot using Robot Operating System 2 (ROS 2) Jazzy with sensor fusion from GNSS-RTK, IMU, and wheel encoders, and tested it on straight, circular, and figure-eight trajectories at 1.0–5.0 m/s in an open area.

    What worked and what didn't

    In the open-area tests, PP-DSC achieved mean lateral deviations of 0.05, 0.07, and 0.08 m on the straight, circular, and figure-eight trajectories, which the abstract says was a 68–82% improvement over standard Pure Pursuit. In the simulated biodiesel plant, standard Pure Pursuit outperformed the Safety-integrated PP-DSC by 15.6% overall, although the safety-integrated version still showed 11–17% improvement in moderate-curvature sections and added less than 1% tracking overhead.

    What to keep in mind

    The industrial test was a simulation in an empty fruit bunch biodiesel plant, not a physical deployment. The abstract also indicates that the safety-integrated approach was less effective in tight turning radii of 5–9 m, so the results depend on site geometry.

    • PP-DSC reduced mean lateral deviation to 0.05, 0.07, and 0.08 m in open-field tests.
    • The abstract reports 68–82% improvement over standard Pure Pursuit in those outdoor trajectories.
    • A Safety-integrated PP-DSC variant used an F&EI-based safety factor to reduce speed in hazard zones.
    • In the plant simulation, standard Pure Pursuit outperformed the safety-integrated version by 15.6% overall.
    • The safety-integrated version still showed 11–17% improvement in moderate-curvature sections and added less than 1% overhead.

  • Digital transformation is linked to higher market value in Chinese manufacturers

    What the study found

    The study found that digital transformation is positively associated with market value in Chinese manufacturing firms. The authors also report that human capital, technological innovation, and operational efficiency help explain this relationship.

    Why the authors say this matters

    The authors conclude that digital transformation can support long-term value creation for managers. They also suggest that strategic orientation and external conditions, such as ESG performance and industry competition, shape how much value digital transformation produces.

    What the researchers tested

    The researchers used Dynamic Capabilities Theory, which is the idea that firms improve by adapting and reconfiguring their resources and skills. They analyzed 23,440 firm-year observations from Chinese manufacturing firms between 2012 and 2024, using Tobin's Q as the measure of market value.

    What worked and what didn't

    Digital transformation was found to positively affect market value. The relationship was mediated by human capital, technological innovation, and operational efficiency, and it was stronger when ESG performance was strong and when industry concentration was higher. State-owned and larger firms benefited more, and firms with analytical strategies achieved the highest returns.

    What to keep in mind

    The abstract does not describe specific limitations. The summary available here is limited to Chinese manufacturing firms and the variables named in the abstract, so the findings should be read within that scope.

    • Digital transformation was positively associated with market value in Chinese manufacturing firms.
    • Human capital, technological innovation, and operational efficiency helped mediate the relationship.
    • Strong ESG performance amplified the benefits of digital transformation.
    • Greater industry concentration strengthened the effect of digital transformation.
    • State-owned and larger firms appeared to benefit more than others.
    • Firms with analytical strategies showed the highest returns.

  • Lean robotics improved efficiency in an SME packaging case study

    What the study found

    The study found that a scalable lean robotics system, combined with lean principles, collaborative industrial robotics, and Industrial Internet of Things monitoring, improved productivity and resource efficiency in one small and medium-sized enterprise packaging process. The authors report a three- to four-fold reduction in preparation time per unit, more efficient use of stone paper and adhesive, and less repetitive manual handling.

    Why the authors say this matters

    The authors conclude that the findings help advance understanding of lean robotics for sustainable production in small and medium-sized enterprises. They also say the work offers practical guidelines for designing scalable, resource-efficient robotic cells.

    What the researchers tested

    The researchers developed a lean robotics design approach that brought together lean principles, collaborative industrial robotics, and Industrial Internet of Things monitoring. They applied it in a real-world case study of a "Fold Station" robotic cell, where stone paper sheets were destacked, glued, and formed into cylindrical plant protectors.

    What worked and what didn't

    Key performance indicators were measured before and after implementation, including cycle time, material utilization, process stability, and manual workload. The reported results showed faster preparation per unit, better use of stone paper and adhesive, and reduced repetitive manual handling; the abstract does not report any specific outcomes that did not improve.

    What to keep in mind

    The abstract describes a single real-world case study, so the findings are based on one SME packaging process. Limitations beyond this scope are not described in the available summary.

    • A scalable lean robotics system was applied in an SME packaging process.
    • The study reports a three- to four-fold reduction in preparation time per unit.
    • Stone paper and adhesive were used more efficiently after implementation.
    • Repetitive manual handling decreased after the robotic cell was introduced.
    • The approach combined lean principles, collaborative industrial robotics, and Industrial Internet of Things monitoring.

  • Fatigue performance depended mainly on surface integrity and defects

    What the study found

    The study found that axial fatigue performance in laser powder bed fusion Ti6Al4V was mainly governed by surface integrity and defect population rather than changes in microstructure. Lower layer thickness and surface finishing were associated with better endurance strength.

    Why the authors say this matters

    The authors conclude that finer layers and surface finishing can improve endurance strength in this material, although they note this comes at the cost of reduced build productivity. The study suggests that controlling surface condition is important for fatigue performance.

    What the researchers tested

    The researchers produced Ti6Al4V specimens using laser powder bed fusion, also called PBF-LB, with two layer thicknesses: 40 µm and 80 µm, under the same process parameters. They then carried out tensile and axial fatigue tests, along with microstructural analysis using field-emission scanning electron microscopy and electron backscatter diffraction.

    What worked and what didn't

    Both processing conditions produced fully martensitic α′ microstructures, but the 40 µm builds had finer lamellae and smaller prior-β grains because of higher cooling rates. Tensile tests showed higher ductility for the 40 µm specimens while strength stayed similar, and axial fatigue performance was better with lower layer thickness, electropolished surfaces, and diagonal orientation.

    What to keep in mind

    The abstract does not describe sample size, statistical details, or numerical fatigue values. It also does not provide limitations beyond noting the tradeoff between improved fatigue performance and lower build productivity.

    • Axial fatigue performance was mainly linked to surface integrity and defect population.
    • Lower layer thickness improved fatigue performance in the tested Ti6Al4V specimens.
    • Electropolished surfaces and diagonal orientation were associated with better fatigue results.
    • Both layer thicknesses produced fully martensitic α′ microstructures.
    • The 40 µm builds had finer lamellae and smaller prior-β grains than the 80 µm builds.

  • Scheduling model addresses multiple resources in pallet automation systems

    What the study found

    The study presents a multiresource-constrained flexible job shop scheduling problem for pallet automation systems, with fixture pallets and setup stations included alongside machines. The authors report a model and algorithmic approach designed to produce feasible schedules while minimizing makespan, which is the total time needed to finish all jobs.

    Why the authors say this matters

    The authors say this matters because pallet automation systems are important in flexible manufacturing and prior work has mostly focused on machines while overlooking fixture pallets and setup stations. The study suggests that addressing the coupling between resource selection and operation sequencing is important for this setting.

    What the researchers tested

    The researchers studied a multiresource-constrained flexible job shop scheduling problem under pallet automation systems, referred to as MRFFS. They proposed a mixed-integer programming model, a four-layer encoding scheme, a decoding method called time period insertion based on the intersection of available time of multiple resources, and a search algorithm based on critical paths and points mutation. They also designed four case studies to examine the approach.

    What worked and what didn't

    The abstract says the new decoding method was intended to obtain feasible schedule solutions and shrink the search space. It also says the search algorithm was developed to balance exploration and exploitation, and that the four case studies were used to demonstrate validity and effectiveness. The abstract does not provide detailed numerical results or comparisons.

    What to keep in mind

    The available summary does not report the case study data, quantitative performance values, or direct comparisons with other methods. The abstract also does not describe specific limitations beyond noting that research on pallet automation systems is limited.

    • The study addresses scheduling in pallet automation systems with machines, fixture pallets, and setup stations.
    • It proposes a mixed-integer programming model to minimize makespan.
    • A four-layer encoding scheme and a new decoding method are introduced to help find feasible schedules.
    • A search algorithm based on critical paths and points mutation is developed.
    • Four case studies are mentioned as evidence of validity and effectiveness.

  • Heat treatment improved strength and hardness in WAAM Inconel 718

    What the study found

    The study found that post-deposition heat treatment changed the mechanical behavior of WAAM-CMT (Wire Arc Additive Manufacturing with Cold Metal Transfer) deposited Inconel 718. Annealing at 1100 °C for two hours followed by furnace cooling improved strength and hardness, but slightly reduced impact toughness.

    Why the authors say this matters

    The authors conclude that this trade-off offers an optimal balance for specific engineering requirements. They also suggest that WAAM-CMT fabricated and heat-treated Inconel 718 shows promise for engineering applications that demand high performance and durability.

    What the researchers tested

    The researchers fabricated an Inconel 718 wall using the WAAM-CMT process and compared specimens in the as-deposited condition with specimens after post-deposition heat treatment. They evaluated tensile behavior, impact toughness, and microhardness, and examined the microstructure with optical microscopy, x-ray diffraction (XRD), and scanning electron microscopy (SEM) of fractured samples.

    What worked and what didn't

    According to the abstract, annealing at 1100 °C for two hours followed by furnace cooling improved strength and hardness. The same treatment slightly reduced impact toughness, indicating a trade-off between these properties.

    What to keep in mind

    The abstract does not provide detailed numerical results, so only the direction of the changes is available here. It also does not describe sample size, statistical analysis, or broader testing conditions.

    • The study compared as-deposited and heat-treated Inconel 718 walls made by WAAM-CMT.
    • Annealing at 1100 °C for two hours with furnace cooling increased strength and hardness.
    • Impact toughness decreased slightly after the heat treatment.
    • The researchers used tensile tests, impact tests, microhardness measurements, optical microscopy, XRD, and SEM.
    • The authors describe the treated material as promising for engineering applications.

  • Automated warehousing ranked above manpower-based systems

    What the study found

    The study found that automated warehousing systems were rated higher than manpower-based systems for productivity, safety, and long-term operating expenses. Manual systems were described as better for flexibility and lower initial investment.

    Why the authors say this matters

    The authors conclude that the findings offer practical insight for managers who are evaluating warehouse automation strategies. The study also suggests that combining multiple fuzzy multi-criteria decision-making methods and sensitivity analysis can strengthen the robustness of decision outcomes.

    What the researchers tested

    The researchers applied an integrated fuzzy multi-criteria decision-making framework, which uses fuzzy logic to compare options under uncertainty across several criteria. They combined Fuzzy EDAS, Fuzzy TOPSIS, Fuzzy AHP, and Fuzzy VIKOR, and added sensitivity analysis for Fuzzy EDAS and Fuzzy VIKOR. They evaluated automated and manpower-based warehousing systems using six criteria: productivity, safety, flexibility, initial investment, annual expense, and error rate.

    What worked and what didn't

    Across the evaluation, automated warehousing systems consistently outperformed manpower-based alternatives on productivity, safety, and long-term operating costs. Manual systems retained advantages in flexibility and lower initial investment. The sensitivity analysis was used to test whether rankings changed when criterion weights were altered, and it was presented as supporting result credibility.

    What to keep in mind

    The abstract does not describe the specific warehouse settings, sample size, or data sources used in the comparison. It also does not provide detailed ranking values or statistical measures beyond the reported consistency of the results.

    • Automated warehousing systems ranked above manpower-based systems overall.
    • Automation performed better for productivity, safety, and long-term operating expenses.
    • Manual warehousing retained advantages in flexibility and lower initial investment.
    • Four fuzzy decision-making methods were combined in one framework.
    • Sensitivity analysis was applied to Fuzzy EDAS and Fuzzy VIKOR to test ranking robustness.

  • Nonreciprocal stiffness and damping separately control wave behavior

    What the study found

    The study found that when nonreciprocal stiffness and nonreciprocal damping are combined in an elastic lattice, they form a decoupled control mechanism. In this system, nonreciprocal stiffness governs temporal amplification rate, while nonreciprocal damping independently tunes group velocity and oscillation frequency.

    Why the authors say this matters

    The authors conclude that this decoupling offers a theoretical framework for designing active metamaterials, which are engineered materials with properties not found in ordinary materials, with more versatile control over wave propagation characteristics.

    What the researchers tested

    The researchers systematically investigated wave dynamics in an elastic lattice that combines nonreciprocal stiffness with viscous damping. They first examined how conventional damping counteracts gain, then introduced a non-dissipative form of nonreciprocal damping called gyroscopic damping.

    What worked and what didn't

    The coexistence of nonreciprocal stiffness and nonreciprocal damping produced separate control of different wave behaviors. The abstract reports that nonreciprocal stiffness controlled amplification, while nonreciprocal damping tuned group velocity and oscillation frequency; it also notes enhanced net amplification for slower-propagating waves and boundary-induced wave interference from reflected wave trajectories with different growth rates.

    What to keep in mind

    The abstract presents a theoretical study, and it does not describe experimental validation. It also does not provide detailed limits, device performance values, or implementation constraints in the available summary.

    • The study examined wave dynamics in an elastic lattice with nonreciprocal stiffness and damping.
    • Conventional damping was found to counteract the system's gain.
    • Gyroscopic damping was introduced as a non-dissipative form of nonreciprocal damping.
    • Nonreciprocal stiffness governed temporal amplification rate.
    • Nonreciprocal damping independently tuned group velocity and oscillation frequency.
    • The abstract describes enhanced net amplification for slower waves and boundary-induced wave interference.

  • Digital technologies supported greener warehouse operations

    What the study found

    The study found that digitalization, automation, and robotization can support green logistics in warehousing operations. In particular, a warehouse management system, integrated information systems, and RFID technology were associated with less paper use and more efficient warehouse processes.

    Why the authors say this matters

    The authors conclude that digital technologies already serve as a systematic enabler of green logistics within the organization. They also suggest that the environmental benefits should be measured directly, including changes in energy use and CO2 emissions.

    What the researchers tested

    The researchers combined a scientific literature review and document content analysis with semi-structured interviews with company managers and logistics professionals. The study focused on how digitalization, automation, and robotization support green logistics principles in warehouse operations.

    What worked and what didn't

    The results indicate that implementing a warehouse management system, integrating information systems, and adopting RFID technology reduced paper-based processes, improved picking accuracy and internal routing, and shortened loading and unloading times. These technologies may also decrease the risk of human error and contribute to lower energy use and a reduced environmental footprint. However, the abstract says these environmental benefits have not yet been quantified.

    What to keep in mind

    The study reports qualitative and document-based findings, but it does not provide measured energy or emissions outcomes. The abstract also notes that future research should measure energy use and CO2 emissions under different warehousing scenarios.

    • Digitalization, automation, and robotization were linked to greener warehousing practices.
    • A warehouse management system, integrated information systems, and RFID technology reduced paper-based processes.
    • The technologies improved picking accuracy, internal routing, and loading and unloading times.
    • The abstract says the environmental benefits are implied but not yet quantified.
    • Future research should measure energy use and CO2 emissions in different warehousing scenarios.