Abstract: In this study, to enhance the overall performance of a gantry machining center's crossbeam, static analysis identified critical load conditions (cutting forces, self-weight, and component loads). Dynamic analysis employed Yoshimura's method to establish joint dynamics models, obtaining modal parameters (natural frequencies, mode shapes, and vibration amplitudes). A hybrid optimization approach combining topology optimization and bionic design was implemented: topology optimization first determined optimal material distribution, followed by bio-inspired rib layout refinement inspired by turtle shell morphology. This methodology achieved balanced static-dynamic performance with lightweight design, integrating computational mechanics and biological structural advantages. Read More

Abstract: This paper presents a linkage based photoelectric tracking and pointing platform integrated on a multilegged robotic base for high precision mobile laser alignment. The system uses a two-stage control architecture combining a coarse mechanical linkage for large angle orientation and a fast-steering mirror RC241179 for micro angular correction. Real time sensor fusion is implemented on an NVIDIA Jetson Orin 8 GB module to combine measurements from a VEYE-MV-SC130M CMOS (Complementary Metal-Oxide-Semiconductor) camera, an LR6000 laser rangefinder, onboard IMU and joint encoders. A hierarchical dual loop control scheme is adopted, with a PID linkage loop at 100 Hz for coarse pointing and a high-speed PD mirror loop at 200-400 Hz for fine correction. Experimental validation shows static pointing precision of 0.21 mrad, dynamic root mean square (RMS) pointing error of 0.56 mrad during locomotion, mean tracking delay of 42 ms, and effective disturbance rejection up to 30 Hz. Continuous operation under a 2-kW laser load for 40 minutes produced no beam drift greater than 0.05 mrad and component temperatures within operational limits. These results demonstrate that the proposed integrated design provides compact, thermally stable, and sub milliradian pointing performance suitable for mobile photoelectric tasks such as mapping, inspection and surveillance. Read More

Abstract: Hawthorn, a unique medicinal and edible economic crop in China, is prone to damage and pest infestations during harvesting and transportation, which severely degrade its quality and utilization value. Traditional manual and instrumental detection methods are characterized by low efficiency, strong subjectivity, and destructiveness, failing to meet the demands of large-scale quality inspection. This study focuses on hawthorn as the research object and conducts non-destructive detection of its damage and pests using hyperspectral imaging technology. By reviewing the domestic and foreign research progress in non-destructive detection of fruit damage, the application potential of hyperspectral imaging technology in the micro-damage and microcosmic detection of agricultural products is clarified. A technical route of “sample preparation—hyperspectral image acquisition—spectral preprocessing—model construction and validation” is designed. Spectral preprocessing is implemented via methods such as Standard Normal Variate (SNV) and Savitzky-Golay (SG) smoothing, and a detection system is established by integrating models including Partial Least Squares (PLS), Principal Component Regression (PCR), and Least Squares Support Vector Machine (LS-SVM). This study aims to address issues such as high sample misjudgment rate and redundant spectral information in hawthorn damage, with the expectation of achieving rapid, non-destructive, and accurate recognition. The research findings can provide technical support for quality grading and non-destructive detection in the hawthorn industry, as well as theoretical and practical references for the application expansion of non-destructive detection technology in agricultural products. Read More

Abstract: Epoxy resins are foundational materials for high-performance composites, but their intrinsic brittleness and often weak interfacial bonding with reinforcements limit their full potential. The incorporation of two-dimensional (2D) nanomaterials, such as graphene oxide (GO), clay minerals (montmorillonite, attapulgite), and their hybrids, has emerged as a highly effective strategy to overcome these limitations. This review synthesizes recent progress in modifying epoxy composites with 2D nanomaterials to enhance their overall performance. Key findings indicate that adding small amounts of GO significantly improves the wettability and adhesion between epoxy and reinforcing fibers, leading to a stronger interfacial layer and superior mechanical properties. Hybrid nanofiller systems, such as GO combined with boron nitride or clay minerals co-incorporated with nano-oxides (TiO₂, Al₂O₃), demonstrate synergistic effects, yielding substantial improvements in tribological, thermal, flame-retardant, and dielectric properties by promoting nanoparticle exfoliation and dispersion. Advanced strategies, including the controlled orientation of nanofillers via magnetic fields or compression molding, have proven effective in creating anisotropic conductive pathways and enhancing tribological performance. Despite these advancements, challenges related to nanoparticle agglomeration, interfacial compatibility, and scalable manufacturing persist. Future research should focus on developing multi-functional composites, integrating computational modeling with experimental work, advancing orientation control techniques, and exploring sustainable waterborne epoxy systems. Read More

Abstract: Based on the milling principle of spiral bevel gears, the structure of the spiral bevel gear milling machine and the motion relationships among its axes were analyzed, and a generating machining motion model for spiral bevel gears was established. By integrating the parameters of the milling cutter head with the generating machining motion model, a tooth surface model enveloped by the cutter head was developed. An analysis was conducted on the influence of six milling process parameters—such as angular tool position, radial tool position, and workpiece blank installation angle—on tooth surface deviation. Building on this foundation, an optimization model aimed at minimizing tooth surface deviation was constructed. The L-M algorithm was then employed to iteratively optimize the machining parameters with the goal of reducing the theoretical machining error as much as possible. Read More

Abstract: This study integrates hyper-spectral imaging technology, data mining, and image processing to explore its application in non-destructive quality assessment of strawberries, including evaluations of appearance, maturity, and internal quality. It also investigates the impact of different feature selection algorithms on classification accuracy. The research contributes to the development of automated quality grading systems for off-season strawberries, reducing post-harvest losses and enhancing fruit quality. Key findings include: (1) Analysis of strawberry quality parameters and spectral characteristics changes (2) High-spectral imaging-based strawberry hardness detection method (3) Detection of Soluble Solid Content (SSC) in Strawberries Using Hyper-spectral Imaging Read More

Abstract: In mechanical manufacturing and daily maintenance, it is often necessary to process threaded holes on large components in narrow spaces such as pipes or corners. Traditional machine tools cannot operate due to spatial constraints, while handheld devices struggle to guarantee accuracy. This study designs an auxiliary machining system based on robotic arm technology to address the challenge of threaded hole machining in confined spaces. The manipulator integrates a magnetic base, a feed mechanism, angle and height adjustment devices, a laser positioning system, and a drilling power unit. The rotary cutting motion is achieved by a DC motor driving a gear reducer; the feed motion is accomplished via a manually operated rack and pinion mechanism; and positioning is realized by two linear infrared lasers arranged at a 90° cross angle. This paper focuses on presenting the overall scheme, key mechanism designs, and working principles of the manipulator. It also includes the design and calculation of the rack and pinion transmission for the feed mechanism. Finite element analysis was performed on critical load-bearing components (e.g., the handle) using SolidWorks software to verify structural safety. The design features a small size, high flexibility, and convenient operation, making it suitable for various narrow space scenarios and capable of significantly improving machining efficiency and precision. Read More

Abstract: To address issues such as powder agglomeration and unstable discharges during mixed powder near-dry electrical discharge surface strengthening, a novel method termed Ultrasonic Assisted Powder Mixed Near Dry Electrical Discharge Surface Strengthening (UPMND-EDSS) is proposed. Ultrasonic vibration is employed to disrupt powder agglomerates, preparing a dispersed, homogeneous three-phase medium that enhances the surface quality and properties of the strengthened layer in TC4 titanium alloy. A systematic analysis of the effects of varying ultrasonic vibration on the surface and properties of the strengthened layer reveals: the hardness of the strengthened layer markedly increased under different ultrasonic powers, with an average hardness reaching 1289.06 HV, approximately 3–4 times that of the substrate; when ultrasonic power was increased to 1200 W, the surface quality of the strengthened layer was optimal, with an average microhardness of 1370.4 HV. In summary, the introduction of ultrasonic vibration effectively improves the surface quality of the TC4 titanium alloy strengthened layer. Read More

Abstract: Multi-dimensional manufacturing resources of workstations and workers are collaboratively optimized scheduling technology. A dynamic scheduling model is constructed for the common dynamic disturbances such as equipment failure, worker absenteeism and emergency order insertion in the actual production process. By analyzing the influence range of disturbance events on the production plan, a local rescheduling mechanism based on the affected process set is proposed, and the strategy of combining event-driven and periodic rescheduling is adopted, and the improved APSO algorithm is used to quickly repair and re-optimize the production plan after disturbance. The deviation of the new scheme from the original production plan is reduced, and the robust operation of the production system in a dynamic environment is realized. Read More

Abstract: With the rapid advancement of modern manufacturing toward high efficiency, precision, and sustainability, the extensive application of difficult-to-machine materials such as titanium alloys and carbon fiber reinforced composites in aerospace and other high-tech fields has imposed increasingly stringent demands on cutting tool performance. Coated tool technology, which involves depositing micro- to nano-scale functional thin films onto tool substrates, has emerged as a critical approach to enhance wear resistance, high-temperature durability, and service life of cutting tools. This paper focuses on Physical Vapor Deposition (PVD) technologies, particularly arc ion plating, for tool coating fabrication. It systematically reviews recent research progress in transition metal nitride coatings s well as nanomultilayer coatings. Studies indicate that through compositional optimization and multilayer structural design, coatings can achieve a synergistic improvement in hardness, toughness, thermal stability, and oxidation resistance. These enhancements effectively reduce cutting friction and temperature, inhibit tool wear, and significantly improve performance and longevity in machining difficult-to-cut materials. Coating technology is evolving toward composite, nanostructured, and functionally graded designs, providing essential technical support to address future challenges in efficient and sustainable manufacturing. Read More

Abstract: Laser cladding technology, as an efficient surface modification and remanufacturing method, has attracted widespread attention in the fields of material surface strengthening and repair of failed components due to its concentrated heat input, good metallurgical bonding between the cladding layer and the substrate, and strong controllability of microstructure. Research on laser cladding coatings based on different alloy systems has achieved extensive results in process parameter optimization, microstructural evolution, defect control, and performance enhancement. This paper systematically reviews relevant domestic and international studies on laser cladding coatings published over the past decade, with a focus on the microstructural characteristics and performance of nickel-based, cobalt-based, iron-based, and composite coatings. The mechanisms of microstructure formation during laser cladding and their effects on mechanical properties, wear resistance, and corrosion resistance are summarized. On this basis, common issues and development trends in current research are analyzed and discussed, aiming to provide references for further studies and engineering applications of laser cladding coating technology. Read More

Abstract: With the development and widespread application of advanced machining technologies such as difficult-to-machine materials and green dry cutting, the cutting environment for tools has become increasingly harsh, leading to continuous updates and iterations of tool coating materials. Coatings have evolved from binary coatings to multi-component coatings; structurally, they have progressed from single-layer to multi-layer and high-entropy alloy coatings. This article summarizes the preparation methods of hard coatings, the current development status of tool coatings, and their applications. It introduces the characteristics and application limitations of the two major preparation techniques: chemical vapor deposition (CVD) and physical vapor deposition (PVD). It analyzes the performance advantages and development trends of binary and multi-component coatings, high-entropy alloy coatings, and self-lubricating coatings. The article points out that the future of hard coating technology will be directed towards sustainability, high performance, multifunctionality, and intelligence to meet complex processing demands and promote the sustainable development of the manufacturing industry. Read More

Abstract: Due to its excellent properties such as high melting point, high hardness, strong corrosion resistance and low saturated vapor pressure, refractory metal W has been widely used in aerospace, nuclear industry, electronics and other fields. However, due to the scarcity and high cost of W resources, its large-scale application in large or complex structural components is severely restricted. In this context, the popularization and use of surface coating technology can not only prepare high-performance W-based coatings on the surface of low-cost substrates, but also solve the cost problem of W resource shortage. At present, the preparation technology of W-based coatings has formed a diversified pattern. Physical vapor deposition, chemical vapor deposition, spraying technology, laser cladding technology and electroplating and other methods each have unique advantages and applicable scenarios. This article will systematically sort out the preparation technology, performance optimization strategies and application status of tungsten-based coatings, analyze the existing problems in current research, and look forward to its future development direction. Read More

Abstract: With the increasing attention of human to resource conservation and environmental protection, green dry cutting technology has been widely concerned. In the dry cutting process, if the protective coating with self-lubricating function is applied on the surface of the tool, the coefficient of friction can be reduced, the cutting heat can be reduced, the temperature of the cutting zone can be effectively reduced, the anti-wear and high-temperature resistance of the tool can be enhanced, the tool chipping can be inhibited, the service life can be prolonged, the processing efficiency can also be improved, and the surface processing quality of the workpiece can be improved. However, for high-hardness coatings, as the temperature rises, the tool will often appear to adhere to oxidation, which requires the use of the coating itself to produce a lubricating effect, so as to reduce the occurrence of such situations. In addition, V reacts with oxygen during friction to form Magnéli phase oxide V2O5 with lubricating effect to achieve a friction reduction effect. In this paper, the crystal structure, commonly used preparation methods, and performance characterization of vanadium carbide (VC) coatings, a self-lubricating coating with high hardness and low friction in a wide temperature range are introduced. Read More

Abstract: As a critical component of the AC double-swing angle milling head, the A-axis support significantly influences its dynamic and static performance. To reduce its mass while meeting static and dynamic requirements, systematically optimize the A-axis support structure, enhance the operational performance of the milling head, and lower material costs, a method combining topology optimization and multi-objective optimization is proposed. The original static and dynamic performance of the A-axis support is analyzed, and optimization objectives are defined. Topology optimization is then employed to identify optimizable regions of the A-axis support, based on which the structure is reconstructed.Based on the topology optimization results, a mathematical model is established with design variables including the wall thickness, rib thickness, and lightening hole size of the A-axis support. The optimization objectives are to minimize mass and maximize the first-order natural frequency, with deformation as the constraint. The Central Composite Design (CCD) method is used to obtain initial sample points, a Kriging model is constructed to establish the response surface, and finally, the Multi-Objective Genetic Algorithm (MOGA) is applied for optimization. After optimization, the deformation of the A-axis support is less than before, meeting the static stiffness requirement. The mass is reduced by 13.87%, achieving the lightweight objective, and the total deformation is decreased by 22.1%, indicating improved static performance. Read More

Abstract: To address the challenges of low stiffness, high deformability, weak positioning references, and the coexistence of multiple constraint bases during the assembly of large and complex thin-walled components, an automated assembly method based on a six-axis industrial robot integrated with binocular vision is proposed, enabling high-precision and coordinated docking in the assembly process of large irregular thin-walled parts. First, an error propagation analysis is conducted for the irregular thin-walled components, and the maximum allowable deviation domain in both translational and rotational spaces that ensures successful assembly is derived. On this basis, a staged assembly strategy following the principle of “initial positioning, primary docking, and secondary constraint” is proposed. The robot first uses binocular vision to estimate the pose deviation of thin-walled part 1 with respect to the locating pins on the fixed base and plans the target TCP pose to achieve pin–hole alignment. Subsequently, the tongue-and-groove (rabbet) mating between thin-walled parts 1 and 2 is performed. Finally, thin-walled part 2 is guided by vision to align with the locating pins on the movable base, completing secondary positioning and constraint, thereby realizing a multi-datum closed-loop assembly. An adaptive pose-error compensation mechanism is incorporated into the assembly process, enabling the robot to satisfy geometric assembly constraints even in the presence of initial fixturing errors and elastic deformations of the thin-walled components. The experimental results demonstrate that, under the combined constraints of binocular reconstruction errors and the robot’s repeatability, the proposed method can reliably achieve multi-datum automatic assembly of large-scale irregular thin-walled components. It significantly reduces the reliance on manual alignment and improves both the assembly success rate and consistency, providing an effective technical pathway for the robotic … Read More

Abstract: Brushless Direct Current (BLDC) motors are widely utilized in industrial automation, intelligent robotics, military, new energy vehicles, consumer electronics, and aerospace due to their high efficiency and reliability. To meet the demand for sensorless control across the full-speed range, this paper investigates and implements a composite rotor position observation method based on High-Frequency Injection (HFI) and Sliding Mode Observer (SMO) under the Field-Oriented Control (FOC) framework: the HFI method is employed to extract rotor position information during zero and low-speed stages, while the system switches to the robust SMO for observation during medium and high-speed stages. Secondly, to address the chattering issue commonly occurring at the switching instant between the two algorithms, a smooth weight switching algorithm based on a cubic S-curve is designed. Matlab/Simulink simulation results demonstrate that the proposed scheme not only ensures stable motor operation across the full-speed range but also reduces the peak angular error of chattering by approximately 50% compared to non-switching algorithms, verifying the effectiveness and superiority of the proposed composite rotor position observation method in full-speed range sensorless control. Read More