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ADVISORY-BASED PRODUCT CONFIGURATOR USED IN CHILLER CONFIGURATION AND EVALUATION
No full textThis article presents the architecture and functional principle of an advisory-based
product configurator. The program is used to create new and modify similar product configurations and is intended for users without in-depth expertise in technical fields. Due to its architecture, the configurator is designed to utilise the knowledge stored in the knowledge database. The selection is based on a combination of fuzzy inference rules and mapping techniques. Knowledge
regarding the product is captured by using component-based matrices. The possibility of adding new knowledge and new rules is also provided. All this enables the configurator to link customer requirements and offers the possibility of selecting one or more products. In addition, it evaluates possible product variants based on the parameters specified by the user. The graphical
representation of the results obtained includes the product technical documentation as well as a matrix representation of all the selected components and modules. The functional principle and evaluation of the product selection are demonstrated using a case study of a chiller for installation in an industrial plant. During the selection and evaluation of the chiller, better system performance is achieved with a chiller that has a water-based condenser
DEVELOPMENT OF METHODS OF TESTING THE RESISTANCE OF MATERIALS IN HYDRODINAMIC CONDITIONS
No full textThe paper presents the results of cavitation resistance testing of different types of materials (metal, ceramic, polymer, composite). Methods of characterization of materials in hydrodynamic conditions of exploitation are defined-ultrasonic vibration method with a stationary sample, scanning electron and optical microscopy, methods of testing mechanical properties. The change in the mass of the material as a function of the cavitation time was monitored and the cavitation speed was determined as an indicator of the resistance of the material. The cavitation resistance of the material was determined based on the value of the cavitation speed and the analysis of the morphology of the surface damage. The formation and development of damage to the surface of the material is monitored using a scanning electron microscope. A comparative overview of test results is presented as a basis for material selection in hydrodynamic conditions. Based on the test results, the correlation of the mechanical properties of the material, primarily strength and hardness structural characteristics (grain size and shape) and properties of the material's resistance to the effect of cavitation was determined. It has been shown that the applied methods are suitable for the quick determination of resistance properties and the selection of all types of materials under cavitation conditions
The Examples of Machine Vision in Agriculture
No full textMachine vision has been involved in the research and
practical application of various phases of agricultural production
since several decades ago. It includes classic image processing
techniques that use different color spaces, as well as hyperspectral
imaging, which can encompass near and far infrared, UV and X-
rays. Apart from classic machine vision methods, the application
of artificial neural networks and machine learning (especially deep
learning) is currently causing considerable improvement in
agricultural research and practice. In this paper, the principles of
the selection of the different machine vision methods in different
agricultural applications is considered. Special attention is paid to
the examples of the applications of convolutional neural networks
in sorting of agricultural products
FLEKSIBILNI ROBOTSKI HVATAČI U INDUSTRIJSKOM OKRUŽENJU– PREGLED POSTOJEĆIH MEHANIČKIH STRUKTURA
No full textHvatanje i manipulacija objektima spadaju u klasu osnovnih zadataka robotskih sistema. Robotski hvatači omogućavaju da se ovi zadaci realizuju i služe kao jedinstveni mehanički interfejs između robotskog sistema i okruženja, odnosno objekata manipulacije. Razvoj robotskih hvatača uslovljen je različitim zahtevima, među kojima se mogu izdvojiti stabilnost hvatanja, izbegavanje
proklizavanja, izbegavanje oštećenja objekta manipulacije i hvatanje objekata različitih oblika,
dimenzija i materijala. U uslovima velike varijantnosti objekata kojima se manipuliše javlja se potreba za razvojem hvatača sa ugrađnim visokim stepenom fleksibilnosti koji umnogome imitiraju sposobnosti ljudske šake. U ovom radu će biti izvršen pregled različitih mehaničkih struktura koje se koriste prilikom projektovanja podaktuiranih fleksibilnih robotskih hvatača i robotskih šaka
SAMPLE PREPARATION FOR CAVITATION EROSION TESTING OF 3D-PRINTED METAL
No full textCavitation erosion is a common occurrence in machine parts and elements operating under cavitation conditions (presence of high-speed working liquid in contact with parts’ working surfaces). This paper describes the comprehensive preparation of samples for testing resistance to cavitation erosion. The samples are 3D-printed metal parts, which is significant considering the increasing use of additive manufacturing technologies in the production of machine parts. The test samples were obtained by recycling samples previously used in rotational bending tests. These samples were made from MS1 maraging steel powder, 3D printed using Direct Metal Laser Sintering (DMLS). The study follows ASTM standard G32-16 for cavitation erosion testing, using a vibrating apparatus with a water bath for immersing the test samples. Samples will be subjected to cavitation for 1, 2, and 4 hours, with periodic mass loss measurements. The obtained data will be used to determine the cavitation rate of the tested material. Additionally, optical and SEM structural and morphological analyses will be conducted before and after testing to characterize the erosion damage process
Reverse engineering and finite element analysis of Ti-6Al-4V orthopaedic hip implants
No full textThe goal of the research presented is to combine reverse engineering methodologies with a numerical approach to analyse the structural integrity of artificial hip implants made of Ti-6Al-4V alloy subjected to different types of loads. In this way, numerical models validate the adopted methodology for obtaining implant geometry using 3D scanning, while also providing valuable insight into the behaviour of hip implants under different static loading cases. Since 3D scanning is proven as efficient and reliable for obtaining accurate geometry of various types of implants, it is applied in this research. Following a detailed development of a hip implant model geometry, involving 3D scanning and refining the obtained point cloud to a level that would realistically represent the actual hip implant, numerical models are made based on the obtained geometry. Results of these simulations using the finite element method in ANSYS® software have provided realistic values of stresses in most critical areas of the hip implant. The precise value of load that would produce plastic strain on the implant is also determined and is used as the limit criterion for selecting load cases for further analysis. This analysis would involve the assessment of fatigue life of hip implants with the same geometry and the same material while assuming the presence of a crack in the most critical area
Mathematical modeling of the repair of worn cardan needle roller bearings
No full textThis paper focuses on the repair of worn universal joints (U-joint), specifically the needle
bearing of the Cardan shaft. U-joint are widely used in automotive applications to compensate for
misalignment between connected shafts. Over time, due to excessive torque, vibration, shock load
and improper lubrication, these joints experience wear and lose their operational capability. The wear
is particulary evident in the needle bearings, which are crucial components that ensure smooth
rotation by reducing friction between the cross journals and yokes. The research presented in this
paper proposes a methodology for restoring the worn elements of U-joints, focusing on the precise
removal of damaged surface layers and the dimensional reconfiguration of the parts. The repair
process involves recalculating the necessary dimensions of the cross journals and needle rollers to
restore the required internal clearance within the bearing after reassembly. Additionally, the study
introduces a mathematical model that accounts for the relationship between the diameter of the
reconditioned parts and the number of needle rollers in the bearing, ensuring optimal performance
after repair. There is also outlines a practical application of this model using MATLAB code for
determining the corrected dimensions, facilitating the restoration process while preserving the
original functional characteristics of the U-joints. Finally, the implications of the repair on the
operational lifespan and load distribution within the bearing are discussed. Highlighting the
importance of maintaining the correct radial clearance to extend the service life of the U –joint and
avoid premature failures
PROJEKTOVANJE I IZRADA OKVIRA BESPILOTNE LETELICE PRIMENOM GENERATIVNOG DIZAJNA I ADITIVNIH TEHNOLOGIJA
No full textU ovom radu je prikazan proces projektovanja prototipa okvira za bespilotnu letelicu primenom generativnog dizajna u okruženju Autodesk Fusion i njegova izrada primenom aditivnih proizvodnih tehnologija, konkretno postupkom fotopolimerizacije u kadi. Jedan od značajnijih napredaka u proizvodnoj industriji predstavlja razvoj aditivnih proizvodnih tehnologija, koje omogućavaju izradu kompleksnih struktura. Ove tehnologije u kombinaciji sa generativnim dizajnom, koji koristi algoritme i veštačku inteligenciju za stvaranje optimizovanih oblika, transformišu tradicionalne pristupe u dizajnu i proizvodnji. Bespilotne letelice, kao jedan on najbrže rastućih segmenata u vazduhoplovnoj industriji, predstavljaju idealnu platformu za primenu ovih agilnih tehnologija, sa ciljem izrade lakših i funkcionalno prilagođenijih letelic
Integracija aditivne tehnologije i mehaničke analize za epruvetu auksetičke strukture
No full textMaterijali sa negativnim Poasonovim koeficijentom su prepoznati kao auksetički materijali. Fleksibilna fotopolimerna smola je korišćena za uzorke, koji imaju auksetičku strukturu u vidu cilindrične školjke. Uzorci su štampani na LCD stampaču od fleksebilne smole koja strukturi daje elastična svojstva tokom testa sabijanja. Pomoću industrijske kamere dimenzionalne promene su zabeležene za dalja ispitivanja. Eksperimentalni rezultati metoda korelacije digitalne slike prikazuju različite scenarije za uzorke sa različitim dimenzijama strukture. Analizirani rezultati daju temelj za buduća istraživanja koja daju perspektivu potencijalnih aplikacija i proizvodnih varijacija auksetičkih struktura
Artificial Intelligence Application and Scenario Planning Methodology In The Green Economy
No full textThe integration of artificial intelligence (AI) in the green economy presents both opportunities and
challenges in addressing environmental sustainability. This abstract provides a concise overview of the
advantages and drawbacks associated with AI deployment in green sectors. On the one hand, AI technologies
such as machine learning, data analytics, and optimization algorithms offer immense potential to enhance
resource efficiency, optimize energy systems, and facilitate sustainable decision-making processes. By
analyzing large datasets and identifying patterns, AI can optimize energy consumption, streamline waste
management, and accelerate the transition to renewable energy sources with the goal of green economy.
However, the widespread adoption of AI in the green economy also raises concerns regarding data privacy,
algorithmic bias, and job displacement. Additionally, the energy-intensive nature of AI training and
computing poses environmental challenges, potentially offsetting the environmental benefits gained from its
implementation. Therefore, while AI holds promise as a tool for advancing environmental sustainability in
the green economy, careful consideration of its implications is necessary to maximize its positive impacts and
mitigate potential risks