Browse Topic: Fabrication

Items (2,758)
The metal inert-gas (MIG) welding technique employed for aluminum alloy automotive bumpers involve a complex thermo-mechanical coupling process at elevated temperatures. Attaining a globally optimal set of model parameters continues to represent a pivotal objective in the pursuit of reliable constitutive models that can facilitate precise simulation of the welding process. In this study, a novel piecewise modified Johnson-Cook (MJ-C) constitutive model that incorporates the strain-temperature coupling has been proposed and developed. A quasi-static uniaxial tensile model of the specimen is constructed based on ABAQUS and its secondary development, with model parameters calibrated via the second-generation non-dominated sorting genetic algorithm (NSGA-II) method. A finite element simulation model for T-joint welding is subsequently established, upon which numerical simulation analyses of both the welding temperature field and post-welding deformation can be conducted. The results
Yi, XiaolongMeng, DejianGao, Yunkai
To obtain real-time tire wear status during vehicle operation, this paper proposes a tire wear detection method based on signal analysis. Firstly, PVDF piezoelectric thin film sensors are pasted in the center of the airtight layer of tires with different degrees of wear to collect tire stress data under different working conditions. Secondly, filter and extract the time-domain and frequency-domain feature information of the collected data to construct a feature dataset. Finally, a deep regression model is established to train the feature dataset and achieve real-time detection of tire damage status. The results indicate that the prediction algorithm based on signal analysis and feature extraction achieves a maximum error of 0.3mm in tire wear detection, demonstrating high accuracy in tire wear detection. Providing tire information for safe driving of vehicles has high industrial application value.
Xianyi, XieYang, HaoJin, Lisheng
Shared autonomous vehicles systems (SAVS) are regarded as a promising mode of carsharing service with the potential for realization in the near future. However, the uncertainty in user demand complicates the system optimization decisions for SAVS, potentially interfering with the achievement of desired performance or objectives, and may even render decisions derived from deterministic solutions infeasible. Therefore, considering the uncertainty in demand, this study proposes a two-stage robust optimization approach to jointly optimize the fleet sizing and relocation strategies in a one-way SAVS. We use the budget polyhedral uncertainty set to describe the volatility, uncertainty, and correlation characteristics of user demand, and construct a two-stage robust optimization model to identify a compromise between the level of robustness and the economic viability of the solution. In the first stage, tactical decisions are made to determine autonomous vehicle (AV) fleet sizing and the
Li, KangjiaoCao, YichiZhou, BojianWang, ShuaiqiYu, Yaofeng
Since the rapid development of the shipping and port industries in the second half of the twentieth century, the introduction of container technology has transformed cargo management systems, while simultaneously increasing the vulnerability of global shipping networks to natural disasters and international conflicts. To address this challenge, the study leverages AIS data sourced from the Vessel Traffic Data website to extract ship stop trajectories and construct a shipping network. The constructed network exhibits small-world characteristics, with most port nodes having low degree values, while a few ports possess extremely high degree values. Furthermore, the study improved the PageRank algorithm to assess the importance of port nodes and introduced reliability theory and risk assessment theory to analyze the failure risks of port nodes, providing new methods and perspectives for analyzing the reliability of the shipping network.
Li, DingCheng, ChengZhao, XingxiLi, Zengshuang
A workable shorter curing cycle is required for the manufacturing of carbon/epoxy towpreg and is crucial for attaining defect-free component consolidation. A rational "processing methodology" based approach is established in this paper, and a cure cycle design protocol is proposed. For thick component, autoclave processing with conventional and shorter curing cycles was used. This has been validated through experimental studies. For thick composites, an uncontrolled exotherm could lead to a cure of the component from the inside out, with high process-postulated residual stresses. To determine and regulate the exotherm cross-linking reaction’s maximal heat generation, thermal tests were conducted. These tests revealed isothermal holds and ramp rates were most effective in lowering the exothermic peak. Based on these findings, a shortened cure cycle was developed and applied to the material system. During the curing process, embedded thermocouples were utilized to track heat production
K, TejasviSingh, P. Sundar
Soft-bending actuators are gaining considerable attention in robotics for handling delicate objects and adapting to complex shapes, making them ideal for biomimetic robots. Soft pneumatic actuators (SPAs) are preferred in soft robotics because to their safety and compliance characteristics. Using negative pressure for actuation, it enhances stability by reducing the risk of sudden or unintended movements, crucial for delicate handling and consistent performance. Negative pressure actuation is more energy-efficient, safe and are less prone to leakage, increasing reliability and durability. This paper involves development of a new soft pneumatic actuator design by comparing various designs and to determine its performance parameters. This paper depicts on designing, and fabricating flexible soft pneumatic actuators working under negative pressure for soft robotic applications. The material used for fabrication was liquid silicone rubber and uniaxial tensile tests were conducted to
Warriar J S, SreejithSadique, AnwarGeorge, Boby
This study investigates the fabrication and characterization of overhanging structures using the Cold Metal Transfer (CMT) pulse based Wire Arc Additive Manufacturing (WAAM) technique, specifically targeting automotive applications on commercial aluminum components. Focusing on optimal welding strategies for overhanging structures, components are fabricated by providing offsets during consecutive deposition of layers, thus producing parts with angles of 45°, 60° and 90° inclinations from the substrate. Three specimens undergo around twenty-five layers of deposition, resulting in structurally sound joints within this specified angle range. AA 4043 electrode is utilized, and welding parameters are optimized through trials by verifying with bead on plate deposition. Successful outcomes are achieved within the specified angle range, though challenges arise beyond 60°, complicating the maintenance of desired weld quality. The study further evaluates the microstructure, microhardness, and
A, AravindS, JeromeA, Rahavendran
A novel sintering method of bridging the two mechanically polished and oriented single-crystals together face-to-face in a non- environmental controlled atmosphere to fabricate the bicrystal substrate of NaCl of macroscopic thickness, with a common zone axis and having planarity over large areas, has been developed. Epitaxial [001] bicrystalline thin face-centered cubic (fcc) metal film of surface-reactive metal-containing tilt grain boundary across the interface is first grown in high vacuum directly by flash deposition on initially fabricated [001] oriented bicrystalline substrate of NaCl. The [001] tilt boundary, thus produced, and is examined by electron microscopy to characterize grain boundary morphology and structure. The findings of some preliminary investigations are then presented. A distinct atomic structure is observed for 310 and 210 inclination. Both HAADF-STEM and Diffraction images reveal that such fabricated high-angle grain boundary accommodates minor deviations from
Dish, NilabhGautam, AbhayBehera, RakeshBanka, HemasunderChavan, Pradeep
Nowadays, there are many technologies emerging like firefighting robots, quadcopters, and drones which are capable of operating in hazardous disaster scenarios. In recent years, fire emergencies have become an increasingly serious problem, leading to hundreds of deaths, thousands of injuries, and the destruction of property worth millions of dollars. According to the National Crime Records Bureau (NCRB), India recorded approximately 1,218 fire incidents resulting in 1,694 deaths in 2020 alone. Globally, the World Health Organization (WHO) estimates that fires account for around 265,000 deaths each year, with the majority occurring in low- and middle-income countries. The existing fire-extinguishing systems are often inefficient and lack proper testing, causing significant delays in firefighting efforts. These delays become even more critical in situations involving high-rise buildings or bushfires, where reaching the affected areas is particularly challenging. The leading causes of
Karthikeyan, S.Nithish, U.Sanjay, S.Sibiraj, T.Vishnu, J.
Aluminum Matrix Composites (AMCs) are gaining traction in aerospace, automotive, and marine industries due to their superior mechanical properties. By integrating hard ceramic particles such as silicon carbide (SiC) and aluminum oxide (Al₂O₃) into aluminum matrices, these composites exhibit enhanced wear resistance and strength-to-weight ratios. This study explores the fabrication and characterization of 6061-T6 aluminum alloy matrix composites, reinforced individually with SiC and Al₂O₃ particles through the squeeze casting technique. The research includes a comprehensive analysis of microstructures and mechanical properties, focusing on compressive strength, Brinell hardness, and tribological behavior. Findings reveal that SiC and Al₂O₃ reinforcements boost compressive strength by up to 27% and 47%, respectively, and increase hardness by up to 29% and 20%, respectively, compared to unreinforced aluminum.
Thirumavalavan, R.Santhosh, V.Sugunarani, S.Regupathi, S.Sundaravignesh, S.
From biology, to genetics, and paleontology, these fields share the DNA as a common and time-proven tool. In science, pressure may be such a tool, shared by thermodynamics, material science, and astrophysics, but not by aerodynamics. Pressure is a shorthand for a force acting perpendicular to a surface. When this surface is reduced to zero, so should the pressure. The wing area of an aircraft acts as a reference area to calculate its parasite drag coefficient. In this scenario, the parasite drag acts as a force over the wing area. If the wing area is reduced to zero, its parasite drag does not, as the fuselage is still generating parasite drag. The ratio of the parasite drag and wing area is an example of a pressure construct that uses a physically irrelevant reference area and has no absolute zero. Pressure constructs, more frequently used than pressures in aerodynamics, are a math-based parameter that preserve dimensional propriety according to the Buckingham Pi theorem but lacks a
Burgers, Phillip
This work pioneers the development of eco-friendly brake pads using coconut fiber and sawdust as reinforcement materials, combined with abrasives and friction modifiers. The innovation lies in the utilization of these natural fibers, which are not only cost-effective and abundantly available but also contribute to the sustainability of brake pad manufacturing. The study aims to explore the feasibility and performance of these organic fibers in brake pad applications. Coconut fiber and sawdust were chosen for their unique properties, such as high strength-to-weight ratio and thermal stability, making them ideal candidates for enhancing brake pad performance. The inclusion of abrasives and friction modifiers further optimizes the braking efficiency and durability of the pads. Comprehensive testing was conducted, including hardness, compression, wear (using a pin-on-disc apparatus), and thermogravimetric analysis (TGA), to thoroughly evaluate the mechanical properties and thermal
Ajay Devan, V.Gunasekar, N.Ravikumar, K.Balaguru, B. A.Deepak, S.
One of the most common materials in the fabrication sectors, especially in the auto sector, is Aluminum alloy. Owing to its low strength to weight ratio, it could be a good fit for a number of applications. The cold working procedure may strengthen the 5XXX series Aluminum alloy, which is not heat treatable and it is also challenging to fuse these alloys together using fusion welding processes. In Recent days, a solid-state welding procedure, Friction Stir Welding (FSW) is used to join this alloy. The impact of FSW process parameters on tensile strength of the joint is examined in this study. Based on the outcomes of the experiment, the highest tensile strength is observed at 900 RPM tool rotation, 100 mm/min welding speed, 1.5-degree tilt angle, and 3.0 tool diameter ratio. Superior strength (246 MPa) of this parameter over its competitors can be attributed to the balanced material flow and the formation of finer grains in the weld region.
Maram, Sreenivasulu ReddyKumar, M. VinothHariram, V.
Hybrid reinforcement-made polypropylene (PP) composites are beneficial over monolithic PP and utilized for various engineering and non-engineering applications. The present investigation of PP hybrid composites is developed with 10 percentages of weight (wt%) of E-glass fiber embedded with 0–6 wt% of silicon carbide via compression technique associated with hot press. E-glass fiber and SiC influencing wear rate, tensile strength, and microhardness behavior of PP and its composites are experimentally investigated. The peak loading of SiC as 6 wt% into PP/10 wt% E-glass fiber is recorded as better wear resistance (0.021 mm3/m), maximum tensile strength value (54.9 MPa), and highest hardness (68 HV). Moreover, the investigation results of hybrid PP composite are better resistance to wear and hiked tensile and hardness behavior compared to monolithic PP. This PP/10 wt% E-glass fiber/6 wt% of SiC hybrid composite is adopted for high-strength to lightweight sports goods applications.
Venkatesh, R.
United States microchip fab plants can cram billions of data-processing transistors onto a tiny silicon chip, but the “clock,” which times the transistors’ operations, must be made separately, which creates a flaw in chip security as well as the supply line. However, a new approach uses commercial chip fab materials and techniques to fabricate specialized transistors to serve as the building block of the timing device.
Human body models have been used for decades to inform efforts in promoting automobile occupant and pedestrian safety. However, many of these models fail to capture the intricacies of individual variability. Cadaveric subjects typically exceed representative age ranges and hence mechanics. Animal subjects typically require specific setups that stray from that which is representative of human crash scenarios. Computational models can only consider so many practical real-world variables. Artificial surrogates, dummies being popular among them, are very popular for reusability and robust data collection. However, even the biomechanically accurate skeletal surrogates available commercially are limited in that they do not consider human variability and skeletal microstructure local variability. The objective of the work herein is to assess computational methods of metastructural variability mimicry by fabrication material. We implement mimicry approaches focusing on bulk isotropic
Hezrony, Benjamin S.C. F. Lopes, PedroBrown, Philip J.
This article presents experimental investigations and machine learning-based analysis on depositions of super duplex stainless steel (SDSS ER2594) material in wire arc additive manufacturing (WAAM) considering the process parameters namely voltage, wire feed rate, torch travel speed, and gas flow rate. Deposition efficiency and surface height values of the accumulated material were measured to build machine learning models using artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). The developed ANN model could predict the deposition efficiency and surface height with mean absolute deviations (MADs) of 8.9% and 16.1%, respectively. The MAD for prediction of the two responses for ANFIS model was found to be 6.1% and 14.9% as compared to the experimental data. Multi-objective optimization was also performed to obtain optimal solutions to achieve desired deposition results. Mechanical properties and microstructures of the deposited materials with optimal
Kumar, PrakashMondal, SharifuddinMaji, Kuntal
Improvements in trace biological molecule detection can have significant impact on healthcare, food safety, and environmental safety industries. Detection of trace biological molecules can be critical to the diagnosis of early onset of diseases or infections. Researchers at NASA Ames Research Center developed an electrochemical, bead-based biological sensor based on Enzyme-Linked Immunosorbent Assay (ELISA) combining a magnetic concentration of signaling molecules and electrochemical amplification using wafer-scale fabrication of microelectrode arrays.
To expand the availability of electricity generated from nuclear power, several countries have started developing designs for small modular reactors (SMRs), which could take less time and money to construct compared to existing reactors.
Photolithography involves manipulating light to precisely etch features onto a surface, and is commonly used to fabricate computer chips and optical devices like lenses. But tiny deviations during the manufacturing process often cause these devices to fall short of their designers’ intentions.
Engineers at UC Berkeley have developed a new technique for making wearable sensors that enables medical researchers to prototype and test new designs much faster and at a far lower cost than existing methods.
To advance soft robotics, skin-integrated electronics, and biomedical devices, researchers have developed a 3D printed material that is soft and stretchable — traits needed for matching the properties of tissues and organs — and that self-assembles. Their approach employs a process that eliminates many drawbacks of previous fabrication methods, such as less conductivity or device failure.
The present work highlights the significance of nanocomposite coatings for their ease of processing and applicability in combating corrosion. Ongoing research is dedicated to the development of an effective nanocomposite hydrophobic coating. A hydrophobic nanocomposite coating was deposited on galvanized iron (GI) using a sol-gel route with polymethylsiloxane (PDMS) reinforced with nano-SiO2. Surface morphology and chemical composition analysis, conducted with scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDAX) and Fourier transform infrared spectroscopy (FTIR), revealed the coating’s structural and compositional attributes. The resulting hydrophobic coating exhibits a water contact angle (WCA) of 104.1°, indicating a 30.45% increase compared to bare GI. Subsequent to these characterizations, the adhesion of the coated GI, rated as 4B per ASTM D3359, is followed by commendable resistance to corrosion, as evidenced by electrochemical tests. The corrosion rate
Kumar, PrakashRamesh, M.R.Doddamani, Mrityunjay
Bio-composites have gained significant attention within the aerospace industry due to their potential as a sustainable solution that addresses the demand for lightweight materials with reduced environmental impact. These materials blend natural fibers sourced from renewable origins, such as plant-based fibers, with polymer matrices to fabricate composite materials that exhibit desirable mechanical properties and environmental friendliness. The aerospace sector's growing interest in bio-composites originates from those composites’ capacity to mitigate the industry's carbon footprint and decrease dependence on finite resources. This study aims to investigate the suitability of utilizing plant-derived flax fabric/PLA (polylactic acid) matrix-based bio-composites in aerospace applications, as well as the recyclability potential of these composites in the circular manufacturing economy. The bio-composite laminate is produced through a compression molding process involving interleaved layers
B S, DakshayiniKancherla, Kishore BabuRaju, BenjaminRoy Mahapatra, Debiprosad
The photochemical etching (PCE) process is distinguished by its capacity to fabricate metal parts with unparalleled accuracy. This process sidesteps the typical stresses and deformations linked to conventional metal-working, like stamping or laser cutting, which can compromise material integrity. Such fidelity is crucial in the manufacture of components for thermal management systems, where material integrity and component precision are non-negotiable for ensuring effective heat creation or dissipation. PCE’s ability to craft parts with smooth, burr-free edges and exact dimensions means heat management components work more effectively, bolstering the reliability and extending the service life of micro electronic devices.
To improve battery performance and production, Penn State researchers and collaborators have developed a new fabrication approach that could make for more efficient batteries that maintain energy and power levels.
Light is used in many ways in sensor technology for high precision applications. For example, white light technology can be used for confocal chromatic sensors and interferometers that can make extremely precise and accurate measurements of distance and thickness down to the sub-nanometer range. This makes them suitable for production monitoring in different industries, including semiconductor fabrication. However, even though both sensor types work with white light technology, the two measurement methods differ significantly, although they complement each other.
This technical paper reports the development of an automatic defect detector utilizing deep learning for “polished skins”. Materials with a “polished skin” are used in the fabrication of the external plates of commercial airplanes. The polished skin is obtained by polishing the surface of an aluminum clad material, and they are visually inspected, which places a significant burden on inspectors to find minute defects on relatively large pieces of material. Automated inspection of these skins is made more difficult because the material has a mirror finished surface. Defects are broadly classified into three categories: dents, bumps, and discolorations. Therefore, a defect detector must be able to detect these types of defects and measure the defects’ surface profile. This technical paper presents details related to the design and manufacture of an inexpensive automated defect detector that demonstrates a sufficiently high level of performance. The system employs multiple line sensor
Aoki, NaofumiOta, TakuyaZaitsu, Masayoshi
Additive manufacturing enables unrivaled design freedom and flexible fabrication of components from a wide range of materials including metals, composites, polymers, and ceramics. The near net shape parts are made by processes like sequential melting or layer-by-layer material deposition with a complex set of processing variables. The sequential nature of the process means that every step can impact the next and thus, tools to evaluate that risk before and during manufacturing are necessary.
Additive manufacturing (AM) is a common way to make things faster in manufacturing era today. A mix of polypropylene (PP) and carbon fiber (CF) blended filament is strong and bonded well. Fused deposition modeling (FDM) is a common way to make things. For this research, made the test samples using a mix of PP and CF filament through FDM printer by varying infill speed of 40 meters per sec 50 meters per sec and 60 meters per sec in sequence. The tested these samples on a tribometer testing machine that slides them against a surface with different forces (from 5 to 20 N) and speeds (from 1 to 4 meters per sec). The findings of the study revealed a consistent linear increase in both wear rate and coefficient of friction across every sample analyzed. Nevertheless, noteworthy variations emerged when evaluating the samples subjected to the 40m/s infill speed test. Specifically, these particular samples exhibited notably lower wear rates and coefficients of friction compared to the remaining
Surendra, S.Sireesha, S.C.P., SivaSuresh, P.
A crucial characteristic of composites, which are manufactured from elements of metal, is their mechanical and durability properties. A variety of reinforcing agents and metal nanoparticles are used to create aluminum-based hybrid metal-material composites. These composites are an advantageous alternative for sectors with limited resources because of their robustness, wear resistance, and thermal management capabilities. Manufacturing sectors employ Taguchi optimisation and Grey relational analysis to enhance the mechanical and durability properties of aluminum-based hybrid metal composites. To comprehend the interrelationships between reinforcing materials such as Al2O3 and SiC at constant fly ash concentration, five responses such as wear loss, tensile strength, elongation rate, impact strength, and hardness were considered and assessed. The Grey Relational Analysis (GRA) method is used to optimise these responses and transform them into Grey Relational Grade (GRG). The Grey
Hemanth Kumar, R.Venkatachalapathy, V.S.K.Arumugam, ThiagarajanLAZAR, MARTIN
Equal Channel Angular Pressing is proven to produce ultrafine-grained to nano-structured materials and is most advantageous in comparison with most severe plastic deformation processes, due to its multi-pass capability. The channel angle is the most dominant process parameter, depending on which the property of the processed material varies significantly. Hence to exploit the advantage of this process and to fabricate materials with tailor-made properties, it is desirable to have access to a wide range of channel angles. Limitations in existing designs restrict this to one fixed angle per die and a variation of the angle demands an entirely new die. Hence a novel die geometry is proposed, where the exit channel is made detachable from the parent die block, permitting flexibility of channel angle. Such a design cuts down the cost of fabricating a die setup for the desired channel angle by as much as 80%, in comparison with the traditional split die configuration where a whole new die
Balasubramanian, M.Prathap, P.Madhu, S.
The basic needs of people are met by the building, fabric, and farming sectors. In addition, the automobile industry significantly contributes to human mobility and is essential to India’s economic expansion. There are numerous research strategies available to improve the bus body building industries. Several investigative approaches for enhancing bus body building industries are available. However, several of these studies merely look at it from the perspective of shop floor activity. Accordingly, when it comes to the execution of process design approaches, there is little practical evidence for accepting Gemba kaizen’s attitude. Hence, the purpose of this article is to present a continuous improvement redesign framework tailored to a specific bus body building industrial sector. The proposed model is structured after a critical examination of Gemba and Kaizen. The results showed that by implementing the improvement initiatives, the number of process activities decreased from 44 to 25
Balakrishnan, S.Senthilkumar, K.Rajkumar, V.Jerold John Britto , J.
The experimental investigation aims to improve natural composite materials aligned with feasible development principles. These composites can be exploited across several industries, including the automobile and biomedical sectors. This research employs date seed powder and neem gum powder as reinforcing agents, along with polyester resin as the base material. The fabrication route comprises compression moulding, causing the production of the natural composite material. This study focuses extensively on mechanical characteristics such as tensile strength, flexural strength, hardness, and impact resistance to undergo comprehensive testing. Furthermore, the chemical properties of the composites are examined using the FTIR test to gain understanding by integrating different proportions of date seed powder (5%, 10%, 15%, and 20%) and neem gum powder (0%, 3%, 6%, and 9%) in the matrix phase. These investigation goals are to evaluate the strength and performance of the fabricated composite
DINESH, D.Boopathiraja, K.P.Rajamurugan, G.Ramamoorthi, R.Yuvaraj, K.P.Babu, N.
Intelligent construction has become an important way to accelerate the transformation and upgrading of the construction industry and promote the high-quality development of the construction industry. As a national pilot city of intelligent construction, Shenyang needs effective policy system support for the development of intelligent construction. Quantitative research of policy text can provide a decision-making basis and path optimization suggestions for formulating and improving intelligent construction incentive policies (ICIP) in Shenyang. This study uses text mining and the Policy Modeling Consistency index (PMC index) model to construct an intelligent construction policy index system. Then it combines the PMC index and PMC surface to evaluate and analyze the text of ICIP in Shenyang quantitatively. The results show that there is still room for improvement in the ICIP in Shenyang. Accordingly, countermeasures and suggestions are put forward for policymakers, enterprises, and
Qi, YizhuoyanLi, LihongKong, Fanwen
Working on the nanoscale gives researchers a lot of insight and control when fabricating and characterizing materials. In larger scale manufacturing, as well as in nature, many materials have the capacity for flaws and impurities that can disrupt their complex structure. This creates several weak points that can easily break under stress. This is common with most glass, which is why it is thought of as such a delicate material.
In recent years, industry adoption of thermoplastic composites (TPCs) in lieu of thermosets and metallic structures has increased for the fabrication of air and launch vehicle components. Manufacturing of TPCs, performed via automated tape laying (ATL) and automated fiber placement (AFP), uses machines that place prepreg tow or tapes on molds in a unidirectional manner, which then undergo cure cycles, autoclaving, and other steps that require special tooling. The process is time, material, and energy intensive, requires large facilities to house equipment, and limits the size, mechanical properties and shapes of the parts manufactured. To address these limitations, NASA’s Langley Research Center has developed a simplified, tool-less automated tow/tape placement (ATP) system.
In the rapidly evolving era of software and autonomous driving systems, there is a pressing demand for extensive validation and accelerated development. This necessity arises from the need for copious amounts of data to effectively develop and train neural network algorithms, especially for autonomous vehicles equipped with sensor suites encompassing various specialized algorithms, such as object detection, classification, and tracking. To construct a robust system, sensor data fusion plays a vital role. One approach to ensure an ample supply of data is to simulate the physical behavior of sensors within a simulation framework. This methodology guarantees redundancy, robustness, and safety by fusing the raw data from each sensor in the suite, including images, polygons, and point clouds, either on a per-sensor level or on an object level. Creating a physical simulation for a sensor is an extensive and intricate task that demands substantial computational power. Alternatively, another
Yousif, Ahmed Luay YousifElsobky, Mohamed
Positioning system is a key module of autonomous driving. As for LiDAR SLAM system, it faces great challenges in scenarios where there are repetitive and sparse features. Without loop closure or measurements from other sensors, odometry match errors or accumulated errors cannot be corrected. This paper proposes a construction method of LiDAR anchor constraints to improve the robustness of the SLAM system in the above challenging environment. We propose a robust anchor extraction method that adaptively extracts suitable cylindrical anchors in the environment, such as tree trunks, light poles, etc. Skewed tree trunks are detected by feature differences between laser lines. Boundary points on cylinders are removed to avoid misleading. After the appropriate anchors are detected, a factor graph-based anchor constraint construction method is designed. Where direct scans are made to anchor, direct constraints are constructed. While in the position where the anchor is not directly observed
Shen, XiangxiangLu, XiongZhu, JiaqiGao, LetianWu, JunxianLu, Yishi
4D millimeter wave radar is a high-resolution sensor that has a strong perception ability of the surrounding environment. This paper uses millimeter wave radar point cloud to establish a static probabilistic occupancy grid map for static environment modeling. In order to obtain a clean occupancy grid map, we classify the point cloud according to the result of dynamic point clustering and project the classified point cloud into the grid map. Based on the distribution and category of millimeter wave radar point cloud, we propose a calculation model of grid occupancy probability. After obtaining the occupancy probability according to the calculation model, we calculate the posterior occupancy probability by using the motion law of self-vehicle and Bayesian filtering, and construct a stable probabilistic occupancy grid map. We test the method on real roads, and the results show that the proposed method can effectively suppress the influence of noise points on the quality of grid map, and
Liu, ChangLu, XinfeiXue, DanWu, Li
To improve battery performance and production, Penn State researchers and collaborators have developed a new fabrication approach that could make for more efficient batteries that maintain energy and power levels.
Centimeter-scale walking and crawling robots are in demand both for their ability to explore tight or cluttered environments and for their low fabrication costs. Now, pulling from origami-inspired construction, researchers led by Cynthia Sung, Gabel Family Term Assistant Professor in Mechanical Engineering and Applied Mechanics, have crafted a more simplified approach to the design and fabrication of these robots.
In this article, we present a spatiotemporal trajectory planning algorithm for emergency obstacle avoidance. Utilizing obstacle and driving environment data from the sensing module, we construct a 3D spatiotemporal grid map. This informs our improved hybrid A* algorithm, which identifies collision-safe, dynamically feasible trajectories. The traditional hybrid A* algorithm is enhanced in three significant ways to make the search practical and feasible: (1) optimizing search efficiency with motion primitives based on child node acceleration, (2) integrating collision risk into the heuristic function to reduce ineffective node exploration, and (3) introducing a One-Shot search based on the Optimal Boundary Value Problem (OBVP) to improve goal state searches. Finally, the algorithm is tested in two scenarios: (1) a vehicle cut-in from an adjacent lane and (2) a pedestrian crossing. Simulation results indicate that our proposed emergency obstacle avoidance trajectory planning method can
Chen, GuoyingYao, JunGao, ZhenhaiGao, ZhengZhao, XuanmingXu, NanHua, Min
Nylon polymer with an optimal blend of Kevlar, fiberglass, and high-speed, high temperature (HSHT) Fiberglass offers improved characteristics such as flexural strength, wear resistance, electrical insulation, shock absorption, and a low friction coefficient. For this reason, the polymer composite manufactured by combining HSHT, Kevlar, and fiberglass with nylon as base material will expand the uses of nylon in the aerospace, automotive, and other industrial applications related to ergonomic tools, assembly trays, and so forth. The proposed work was carried out to investigate the continuous fiber reinforcement (CFR) in nylon polymer using a dual extrusion system. Twenty experimental runs were designed using a face-centered central composite design (FCCD) approach to analyze the influence of significant factors such as reinforcement material, infill pattern, and fiber angle on the fabricated specimen as per American Society for Testing Materials (ASTM) standards. The tensile strength
Kaushik, AshishKumar, PardeepGahletia, SumitGarg, Ramesh KumarKumar, AshishYadav, MohitGiri, JayantChhabra, Deepak
Magnesium alloy, known for its high strength and lightweight properties, finds widespread utilization in various technical applications. Aerospace applications, such as fuselages and steering columns, are well-suited for their utilization. These materials are frequently employed in automotive components, such as steering wheels and fuel tank lids, due to their notable corrosion resistance. The performance of magnesium alloy components remains unimproved by normal manufacturing methods due to the inherent characteristics of the material. This work introduces a contemporary approach to fabricating complex geometries through the utilization of Wire-Electro Discharge Machining (WEDM). The material utilized in this study was magnesium alloy. The investigation also considered the input parameters associated with the Wire Electrical Discharge Machining (WEDM) process, specifically the pulse duration and peak current. The findings of the study encompassed the material removal rate and surface
Natarajan, ManikandanPasupuleti, ThejasreeD, PalanisamyKumar, VKiruthika, JothiPolanki, Vamsinath
The 3D printing technology is an Additive Manufacturing process which is capable of producing the complex shapes. At present there is no other technologies integrating the 3D printing and the CNC machine, thus we adapting a new design of 3D printing setup for CNC machine with some special feature as extruder, it is based on the Fusion Deposition Modelling (FDM) process with the help of the parts like Extruder, Heat Bed, Arduino boards where we are going to design a head of the printer which is to be attached with the BT40 commonly used Tool holder for the CNC milling machines. This extruder plays a vital role in this CNC milling machine for producing 3D printed components of different material and different colour. And this setup is capable of printing high resolution and complex shapes with different material and different colour by means of the heated filament. The post processing process like milling and surface finish can also be done by the CNC Machine. This setup is cost
Deepan Kumar, SadhasivamS, BalakrishnanSaminathan, SathiskumarArun Raj, VDhayaneethi, SivajiE, SoundrapandianVeath Prakash, B
Since there are no typical working conditions in the field of engineering vehicles, this paper implements the construction of driving conditions based on Markov stochastic model and energy management strategy of a multi-mode hybrid mine dump truck based on dynamic programming algorithm under this background. Firstly, on the basis of existing vehicle driving data, we calculate the velocity transfer probability matrix with the Markov stochastic model, and then construct the vehicle driving condition after predicting the velocity. The constructed working conditions are applied to the energy management strategy of dynamic programming algorithm to calculate the energy consumption of the hybrid mining truck. It is proved that this construction method can be applied to the hybrid electric mine dump truck, and the DP based energy management strategy has lower energy consumption.
Jiang, Y.T.Zhao, XinxinZhang, J.G.
This specification covers elemental copper in the form of powder (see 8.5).
AMS D Nonferrous Alloys Committee
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