A Full-Parameter Calibration Method for an RINS/CNS Integrated Navigation System in High-Altitude Drones
Huanrui Zhang, Xiaoyue Zhang, Chunhua Cheng
et al.
High-altitude long-endurance (HALE) UAVs require navigation payloads that are both fully autonomous and lightweight. This paper presents a full-parameter calibration method for a dual-axis rotational-modulation RINS/CNS integrated system in which the IMU is mounted on a two-axis indexing mechanism and the reconnaissance camera is reused as the star sensor. We establish a unified error propagation model that simultaneously covers IMU device errors (bias, scale, cross-axis/installation), gimbal non-orthogonality and encoder angle errors, and camera exterior/interior parameters (EOPs/IOPs), including Brown–Conrady distortion. Building on this model, we design an error-decoupled calibration path that exploits (i) odd/even symmetry under inner-axis scans, (ii) basis switching via outer-axis waypoints, and (iii) frequency tagging through rate-limited triangular motions. A piecewise-constant system (PWCS)/SVD analysis quantifies segment-wise observability and guides trajectory tuning. Simulation and hardware-in-the-loop results show that all parameter groups converge primarily within the segments that excite them; the final relative errors are typically ≤5% in simulation and 6–<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>16</mn><mo>%</mo></mrow></semantics></math></inline-formula> with real IMU/gimbal data and catalog-based star pixels.
Mechanical engineering and machinery, Machine design and drawing
Virtual Influencers vs. Human Influencers in the Context of Influencer Marketing: The Moderating Role of Machine Heuristic on Perceived Authenticity of Influencers
Heejae Lee, Mincheol Shin, Jeongwon Yang
et al.
Abstract While the popularity of virtual influencers in influencer marketing is on the rise, little is known about the reasons behind their increasing popularity. Furthermore, there is also a dearth of research examining why and how virtual influencers could be more effective than human influencers in influencing consumer purchase decisions. Drawing on the concept of perceived authenticity of influencers and machine heuristic, this study investigates the effects of influencer type (virtual influencer vs. human influencer) on the perceived authenticity of consumers. In addition, we also explore if machine heuristic will moderate the perceived authenticity of consumers and whether trust in influencers and purchase intentions will be subsequently associated with the perceived authenticity of the influencer. Results from an online between-subjects designed experiment (N = 130) indicated that virtual influencers were unexpectedly perceived as more authentic than human influencers. Additionally, the perceived authenticity of virtual influencers significantly increased among those with a strong belief in the machine heuristic. Subsequently, we found a positive association between the perceived authenticity of influencers and the extent of consumers’ trust in them. Additionally, trust in influencers was positively associated with consumers’ intention to purchase the products they promoted by the influencers. These findings provide valuable insights into the use of virtual influencers for marketing purposes. Further theoretical and practical implications are discussed.
66 sitasi
en
Computer Science
Development and Evaluation of a Low-Cost CNC Wood Carving Machine for Artisanal Applications
A. A. Sneineh, Wael A. Salah, B. A. Zneid
et al.
Improving the quality of the produced artwork would require the development of computer numerical control (CNC) technology for various wood shaping processes. This paper presents the development and implementation of a CNC wood carving machine. This project aims to produce wood carvings with high precision and low cost. The electronic components were selected, the mechanical frame of the machine was built, and all parts of the machine were assembled and installed. The presented wood carving machine is based on the principle of drawing the desired shape, translating it into G-code, and then sending it to the microcontroller program. The microcontroller sends instructions to the CNC shield, which drives three stepper motors in a synchronized manner in order to produce the desired carving model. The maximum workpiece of the caving machine designed to be 30x30 cm. Experiments were conducted to test the functionality of the proposed CNC wood carving machine. The results showed that the carved models created by this machine had a carving precision range from ±0.1 to ±0.15 mm and a carving speed of approximately 500 rpm. The proposed CNC can be used to produce low-cost artisanal woodwork applications.
Development of Seeder Design and Technologies of Seed Tape Planting
M. Chaplygin, Y. Tsench, A. V. Podzorov
This paper emphasizes the challenges associated with mechanizing and ensuring quality control in the process of sowing seeds using seed tapes (seed ropes). Each examined invention integrates design and technological solutions developed to improve efficiency and effectiveness. (Research purpose) The study aims to examine the development and evolution of aggregated seed tape planters; focusing on their structural features; and component base. (Materials and methods) The study employs a historical-analytical approach drawing on publications from scientific print sources; patent documents from databases such as Espacenet; the Federal Institute of Industrial Property; the Database of Patents of the USSR; and photographic materials. (Results and discussion) The study provides information on the development of the first devices designed for seed tape sowing. It identifies typical design solutions for seed tape sowing technology across different countries. (Conclusions) A review of existing inventions has been conducted; leading to the identification of several promising design and technological solutions for the development of new machines in this category. Specifically; the study highlights the employment of tape-guiding elements that reduce tape breakage and seed damage; as well as tape break detection and tension control systems. It also emphasizes the versatility of the tape-guiding system; which accommodates tapes of different types and sizes. Additionally; the study highlights the incorporation of soil-cultivating units; a disc-anchor coulter for creating an even and compacted seed bed for the seed tape; and a localized irrigation system to accelerate seed germination and facilitate the biodegradation of the tape carrier.
Development of a Mobile Motorized Rice Threshing Machine for Small and Medium Scale Rice Farmers
Nnam Onwuka, Uzoechi Stanley Goodnews, Otuu Ogbonnia Inya
et al.
Aim and Objectives of the Project: The goal of this work is to enhance the production efficiency of a rice threshing machine by making appropriate modifications to the design of the current model. The study aims to develop a mobile, motorized rice threshing machine that delivers high performance and quality output while minimizing time and cost. Study Design: The Sieve holes was made to enter each grain of rice given room for adequate passage of the grains, Suspending the sieve with relief springs to enable it sieve during vibration and also proper selection of the construction materials were the three significant areas considered for modification. Mild steel was chosen for the fabrication of the parts due to its reliability, durability, and resistance to corrosion. Place and Duration: Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria, between October 2023 and September 2024 Methodology: Detailed machine design both parts and assembled were drawn using Solidworks 2015 version. The machine component parts were marked and cut out from the parent materials as specified in the detailed drawing. The cut-out parts were joined using Arc welding process, why some parts were fastened using bolt and nut. A gasoline engine of 3.5 hp, running at and 1500 rpm transmitting a torque of 4.06 Nm causing a rotational motion on the shaft for effective and efficient threshing of the rice. Results: the performance analysis showed that the enlarged sieve holes, provision of suspension spring and closeness of the spikes significantly affected the threshing and sieving rate of the machine. The machine recorded a threshing efficiency of 95.94% and throughput of 46.99 kg/h. when compared with the existing threshing machine. The new machine saved 0.07 h when threshing 30 kg of rice paddy. The result showed that the machine has optimal performance and produces the intended quantity with the recorded efficiency. Conclusion: this study highlights the crucial role of rice in Nigeria’s economy and the challenges faced by local rice producers, particularly in processing good quantity. The design and fabrication of the mechanized rice threshing machine represent a significant advancement in addressing these challenges. By improving threshing efficiency, reducing grain damage, and cutting labor costs, the machine offers a practical solution to the inefficiencies of traditional rice processing methods. With a threshing efficiency of 95.94% and throughput of 46.99 kg/hr., the machine demonstrates a notable improvement in rice processing. Utilizing locally sourced materials, it further promotes local content and self-reliance in machine development. Ultimately, this project stands to enhance rice production in Nigeria, improve productivity for farmers, and bolster the overall economic potential of the rice farming sector.
Tire Wear, Tread Depth Reduction, and Service Life
Barouch Giechaskiel, Christian Ferrarese, Theodoros Grigoratos
Tires are important for the transmission of forces, good traction of the vehicle, and safety of the passengers. Tires also influence vehicle fuel consumption and cause tire and road wear pollution to the environment in the form of microplastics. In the United States, the Uniform Tire Quality Grading (UTQG) for tread wear is reported on the tire sidewall and is used as an indicator of the expected service life of a tire. In Europe, a similar approach that applies tread depth reduction measurements and projection to the minimum tread depth is under discussion. Tread depth measurements will be carried out in parallel with abrasion measurements over the recently introduced abrasion rate test in the United Nations regulation 117. Testing is carried out with an on-road convoy method accompanied by a vehicle fitted with reference tires to minimize the influence of external parameters. In this brief review, we start with a short historical overview of the methods that have been applied so far for the measurement of tire service life. Based on the limited publicly available data, we calculate the average tread depth reduction per distance driven for summer and winter tires fitted both in the front and rear axles of passenger cars (1–1.2 mm for front wheels and 0.5–0.6 mm for rear wheels per 10,000 km). We theoretically estimate the tread mass loss per mm of tread depth reduction (250 g per 1 mm tread depth reduction, depending on the tire size) and we compare the values to experimental data obtained in recent campaigns. We give estimations of the tire service life as a function of the tread wear UTQG (100 times the indicated tread wear rating). We also discuss the projected service life using tread depth reduction and mass loss.
Mechanical engineering and machinery, Machine design and drawing
Self-excited three-passage switching valve capable of generating traveling wave and reversing wave direction
Sho Fukawa, Toshio Takayama
Abstract In recent years, pneumatically driven soft robots have been studied extensively. Usually, these soft robots contain multiple air chambers, and continuous motion such as locomotion is generated by pressurizing them sequentially. However, long air tubes are required when driving a soft robot far from the air pressure source. Consequently, it takes a long time for the air pressure to reach the chamber, and the motion of the soft robot is delayed. In this paper, we propose a device that self-excitedly switches the airflow passage by supplying continuous airflow. The device had two inputs and three outputs. Pressurizing input 1 switched the airflow passage in sequence, whereas pressurizing input 2 reversed the switching order. Connecting this device to a soft robot enables the robot to be driven without using solenoid valves. We experimentally confirmed that this device could drive a soft robot. We also discuss adjusting the motion frequency, switching pressure, and duty ratio in order to apply this device to other soft robots.
Technology, Mechanical engineering and machinery
Enhancing Roundabout Efficiency Through Autonomous Vehicle Coordination
Csaba Antonya, Calin Iclodean, Ioana-Alexandra Roșu
The paper discusses the potential for autonomous vehicles to improve traffic flow on roundabouts, suggesting that their ability to slow down strategically can enhance traffic and reduce pollution on both main and yielding roads. A traffic simulator for a roundabout was developed for a busy intersection of a new city neighborhood. We consider that some of the cars are self-driving, and they are fully aware of the traffic scenario. By optimizing their speed and timing their speed reduction, these vehicles can help maintain a balance between the number and time of crossing vehicles on both the main and yielding roads. This study evaluates the effectiveness of the intervention, demonstrating that autonomous vehicles can significantly improve roundabout efficiency, reducing congestion and pollution. The application of genetic algorithms is highlighted as an effective optimization method to find the right autonomous vehicle’s timing and speed reduction ratio combination on the main road to enhance traffic efficiency.
Mechanical engineering and machinery, Machine design and drawing
Communicating Design Intent Using Drawing and Text
William P. McCarthy, Justin Matejka, Karl D. D. Willis
et al.
Realizing a designer’s intent in software currently requires tedious manipulation of geometric primitives, such as points and curves. By contrast, designers routinely communicate more abstract design goals to one another using an efficient combination of natural language and drawings. What would it take to develop artificial systems that understand how humans naturally convey design intent, and thereby enable more seamless interactions between humans and machines throughout the design process? First, it is vital to establish benchmarks that showcase the full range of strategies that humans use to successfully communicate about design intent. Here we take initial steps towards that goal by conducting an online study in which pairs of human participants – a “Designer” and “Maker” – collaborated over multiple turns to recreate target designs. In each turn, Designers sent messages containing language, drawings, or both to the Maker, describing how to modify an existing design toward the target. We found a preference for communicating using drawings in early turns and observed several multimodal strategies for conveying design intent. By comparing how human Makers and GPT-4V carried out instructions, we identify a gap in human and machine understanding of multimodal instructions and suggest a path for bridging this gap.
4 sitasi
en
Computer Science
The Vehicle Routing Problem with Simultaneous Pick-Up and Delivery under Fuzziness Considering Fuel Consumption
Paraskevi Zacharia, Stavros Stavrinidis
The increasing interest in environmental protection has propelled reverse logistics as a challenging field in supply chain optimization. This paper addresses the vehicle routing problem with simultaneous pick-up and delivery (VRPSDP) while considering fuzzy payloads, with the primary objective of minimizing fuzzy fuel consumption. The VRPSDP with fuzzy payloads poses a computationally intractable challenge, as it involves a fleet of vehicles departing from a central depot to both deliver and collect goods from a dispersed group of customers. To effectively tackle this problem, a genetic algorithm is applied that incorporates the concept of fuzziness. This problem diverges from the traditional VRPSDP by explicitly considering fuel consumption reduction towards environmental sustainability. To validate and assess the feasibility of the proposed approach, a series of test instances are utilized. The numerical results exhibit the efficiency of the proposed method and place emphasis on the influence of uncertainty in the quantities of goods collected and delivered by customers on the resulting solution.
Mechanical engineering and machinery, Machine design and drawing
Computer vision-based visualization and quantification of body skeletal movements for investigation of traditional skills: the production of Kizumi winnowing baskets
Peng Yang, Yuka Furukawa, Migiwa Imaishi
et al.
Abstract This paper explores the application of computer vision and mathematical modeling to analyze the intricate movements involved in weaving a traditional farming tool, the winnowing basket. By utilizing OpenPose algorithms, the study simplifies and visualizes the craftsmen's motions, particularly focusing on wrist movements. Video data of craftsmen in Chiba, Japan, creating Kizumi (place name) winnowing baskets is used as the basis for analysis. The extracted information is used to generate 2D motion trajectories of the wrist, allowing a comparison between beginners who watched parsed videos and those who watched the original videos in terms of skill acquisition and learning time. By visualizing human body behavior and combining statistical results, this study demonstrates the potential of artificial intelligence techniques such as computer vision for observing repetitive human movement and inheriting traditional skills.
Technology, Mechanical engineering and machinery
Linear Quadratic Tracking Control of Car-in-the-Loop Test Bench Using Model Learned via Bayesian Optimization
Guanlin Gao, Philippe Jardin, Stephan Rinderknecht
In this paper, we introduce a control method for the linear quadratic tracking (LQT) problem with zero steady-state error. This is achieved by augmenting the original system with an additional state representing the integrated error between the reference and actual outputs. One of the main contributions of this paper is the integration of a linear quadratic integral component into a general LQT framework. In this framework, the reference trajectories are generated using a linear exogenous system. During a simulative implementation for the specific real-world system of a car-in-the-loop (CiL) test bench, we assumed that the ‘real’ system was completely known. Therefore, for model-based control, we could have a perfect model identical to the ‘real’ system. It became clear that for CiL, stable solutions cannot be achieved with a controller designed with a perfect model of the ‘real’ system. On the contrary, we show that a model trained via Bayesian optimization (BO) can facilitate a much larger set of stable controllers. It exhibited an improved control performance for CiL. To the best of the authors’ knowledge, this discovery is the first in the LQT-related literature, which is a further distinctive feature of this work.
Mechanical engineering and machinery, Machine design and drawing
Design and Testing of Bionic-Feature-Based 3D-Printed Flexible End-Effectors for Picking Horn Peppers
Lexing Deng, Tianyu Liu, Ping Jiang
et al.
To solve the problems of poor adaptability and large sizes of pepper harvesting machinery in facility agriculture to enhance the efficiency and quality of pepper harvesting and ultimately boost farmers’ income, several flexible end-effectors were designed. These end-effectors were tailored to the unique morphologies of horn peppers, drawing inspiration from biomimicry. Subsequently, we conducted experimental verification to validate their performance. Four biological features, namely, the outer contours of a Vicia faba L. fruit, an Abelmoschus esculentus fruit, the upper jaw of a Lucanidae, and a Procambarus clarkii claw, were selected and designed using 3D software. In order to ascertain the structural viability and establish the initial design framework for the test end-effector, a simulation analysis to evaluate the strength and deformation of the flexible end-effector under various pepper-picking conditions was conducted. PLA material and 3D printing technology were used to create the end-effector, and, together with the mobile robotic arm platform ROSMASTER X3 PLUS, they were used to build a test prototype; a pepper tensile test was performed to pre-determine the reasonableness of the picking program, and then a prototype was created for the actual picking of the peppers to compare the picking effectiveness of several types of flexible end-effectors. In six experiments, each flexible end was harvested for 120 horn peppers. The Vicia faba L. flexible end-effector had the lowest average breakage rate. The average breakage rate was 1.7%. At the same time, it had the lowest average drop rate. The average drop rate was 3.3%. The test results indicated that the flexible end-effector that emulated the outer contour characteristics of the Vicia faba L. fruit demonstrated the most favorable outcomes. This design exhibited high working efficiency and the lowest rates of fruit breakage and fruit drops, surpassing both the artificial and traditional machine picking methods and effectively fulfilling the requirements for pepper-picking operations in facility agriculture.
Application of machine learning-based BIM in green public building design
Dan Wang, F. Chang
Public activities are mostly carried out in large public buildings, which are closely related to social management. At present, people’s demand for public building facilities is increasing, its shape evolution is becoming more complex, and the scientific and technological content of construction-related technology is also increasing. The development trend of green public buildings is more and more strong. The traditional building design cannot effectively deal with the energy consumption of public buildings and people’s demand for their performance. This paper introduces BIM and machine learning technology to study their practical application in the design of green public buildings and tests the perfect machine learning algorithm. According to the experimental test results, the building energy consumption decreased by 14.3%, the carbon emission decreased by 11.39%, and the absolute value of PMV thermal comfort decreased by 34.7%, which obviously achieved the optimization effect. BIM technology parametric design can enable the design model formed by conceptual design research to automatically draw construction drawings, detailed drawings and other drawings according to the drawing requirements and standards, thus saving the designer's time and enabling him to transfer the drawing time to the program design. Finally, through experiments, the economy, rationality and operability of using BIM technology to design green public buildings are confirmed. In this paper, machine learning and BIM technology are introduced, so as to carry out design research for green public building design.
11 sitasi
en
Computer Science
Design and Development of a Modernized Cassava Grating Machine
Innocent Nnanna, I. U. Mbabuike, A. Christian
et al.
Aim: To improve the production rate of a grating machine through careful modifications to the design specifications of the existing one. The objective of the study was to develop a modernized cassava grating machine with a high-performance rate and high-quality output at a minimum time and economical cost. Study Design: The mesh surface area and the selection of proper construction materials were the two significant areas considered for modification. Stainless steel was chosen for fabricating the drum, perforated sheet, hopper, and shaft due to its reliability, durability, and resistance to corrosion. Place and Duration: Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria, between August 2020 and October 2022 Methodology: Detailed design drawings of the machine components were drawn with Solidworks 2019. The machine components were machined and assembled. We used an electric motor of 1hp and 1450rpm to transmit a torque of 4.94Nm that caused rotational motion on the shaft for effective and efficient meshing of the cassava roots. Results: The performance analysis showed that the large mesh surface area significantly affects the pulp's production rate. The larger the mesh surface, the larger the quantity of cassava roots to mesh into pulp. The production rate of the modified grating machine was found to be 454.55kg/hr. and the time saved while meshing 100kg of cassava roots was 0.05 hours compared to the existing ones. The result showed that the machine has optimal performance and produces the intended quality in a reduced time with an efficiency of 95.12%. Conclusion: Construction of the machine was carried out with improved design specifications. A careful selection of construction materials helps to achieve the stated objectives. We recommend this machine to all homes for domestic use because of its durability, reliability, affordability, resistance to corrosion, and ability to mesh a large quantity of cassava roots in a reduced time.
Automatisiert erfassbare Daten in der Rinder-, Schweine- und Geflügelhaltung
Stefanie Reith, Philipp Hölscher
Die Generierung einer Vielzahl an Daten bietet in der Tierhaltung vielfältige Möglichkeiten für Optimierungen. Die Hersteller von Sensortechnologien definieren Zielmerkmale, deren Erfassung die Produktion und das Tier-Management erleichtern sollen. Im Stall werden automatische Komponenten sowie auch gänzlich automatisierte Systeme eingesetzt. Es werden nicht nur Kennwerte über die Produktionsleistung, über den Gesundheitszustand, über den Fruchtbarkeitsstatus und über das Tierverhalten ermittelt, sondern ebenso Daten der technischen Anlagen, mit denen der Tierverkehr und andere Prozesse gesteuert werden können. Die automatisierte Datenerfassung ermöglicht also eine kontinuierliche Bewertung tierbezogener Daten, Klima-/Umweltdaten und Anlagendaten. In einer umfangreichen Datenbank für Sensoren zur „Automatisierten Datenerfassung in der Nutztierhaltung“ (AutoDatTier) wurden jeweils für die Tierarten Rind, Schwein und Huhn Sensortechnologien inklusive verschiedener weiterer Informationen zu Sensorart, Funktionsprinzip, Messart, Datenart und –qualität sowie Datenquelle und Auswertung (insgesamt 19 Kriterien) identifiziert und beschrieben. Bei den Sensoren handelt es sich um technische Bauteile, die mittels physikalischer oder chemischer Effekte zur Erfassung physikalischer, chemischer oder elektrochemischer Größen und deren Umwandlung in elektrische Signale dienen. Je nach Hersteller bzw. Software können die Daten im Grafik-, Tabellen- oder Textformat ausgegeben werden. Die Auswertungen zur Sensortechnik in der landwirtschaftlichen Tierhaltung zeigen detailliert den derzeitigen Umfang der Hersteller und der am Markt angebotenen Sensorsysteme sodass Möglichkeiten und Defizite in der Nutztierhaltung abgeleitet und zukünftige Forschungsprojekte darauf abgestimmt werden können.
Agriculture, Agriculture (General)
Back Propagation Neural Network-Based Fault Diagnosis and Fault Tolerant Control of Distributed Drive Electric Vehicles Based on Sliding Mode Control-Based Direct Yaw Moment Control
Tianang Sun, Pak-Kin Wong, Xiaozheng Wang
Distributed-drive vehicles utilize independent drive motors on the four-wheel hubs. The working conditions of the wheel-hub motors are so harsh that the motors are prone to failing under different driving conditions. This study addresses the impact of drive motor faults on vehicle performance, particularly on slippery roads where sudden faults can lead to accidents. A fault-tolerant control system integrating motor fault diagnosis and a direct yaw moment control (DYC) based fault-tolerant controller are proposed to ensure the stability of the vehicle during various motor faults. Due to the difficulty of identifying the parameters of the popular permanent magnet synchronous wheel hub motors (PMSMs), the system employs a model-free backpropagation neural network (BPNN)-based fault detector. Turn-to-turn short circuits, open-phase faults, and diamagnetic faults are considered in this research. The fault detector is trained offline and utilizes rotor speed and phase currents for online fault detection. The system assigns the torque outputs from both healthy and faulted motors based on fault categories using sliding mode control (SMC)-based DYC. Simulations with four-wheel electric vehicle models demonstrate the accuracy of the fault detector and the effectiveness of the fault-tolerant controller. The proposed system is prospective and has potential for the development of distributed electric vehicles.
Mechanical engineering and machinery, Machine design and drawing
Vehicle Directional Cosine Calculation Method
Derek Hall, Timothy Sands
Teaching kinematic rotations is a daunting task for even some of the most advanced mathematical minds. However, changing the paradigm can highly simplify envisioning and explaining the three-dimensional rotations. This paradigm change allows a high school student with an understanding of geometry to develop the matrix and explain the rotations at a collegiate level. The proposed method includes the assumption of a point (P) within the initial three-dimensional frame with axes (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mover accent="true"><mi>x</mi><mo stretchy="false">^</mo></mover><mi>i</mi></msub></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mover accent="true"><mi>y</mi><mo stretchy="false">^</mo></mover><mi>i</mi></msub></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mover accent="true"><mi>z</mi><mo stretchy="false">^</mo></mover><mi>i</mi></msub></mrow></semantics></math></inline-formula>). The method then utilizes a two-dimensional rotation view (2DRV) to measure how the coordinates of point P translate after a rotation around the initial axis. The equations are used in matrix notation to develop a rotation matrix for follow-on direction cosine matrixes. The method removes the requirement to use Euler’s formula, ultimately, providing a high school student with an elementary and repeatable process to compose and explain kinematic rotations, which are critical to attitude direction control systems commonly found in vehicles.
Mechanical engineering and machinery, Machine design and drawing
Modelling and parameter identification of coefficient of friction for deep-drawing quality steel sheets using the CatBoost machine learning algorithm and neural networks
Sherwan Mohammed Najm, T. Trzepieciński, M. Kowalik
The development of models for the coefficient of friction is difficult due to many factors influencing its value and many tribological phenomena that accompany contact between metals (i.e., flattening, ploughing, adhesion), the influence of which also depends on the friction conditions. Therefore, developing an analytical model of friction is difficult. In this article, the CatBoost machine learning algorithm, newly developed by Yandex researchers and engineers, is used for modelling and parameter identification of friction coefficients for three grades of deep-drawing quality steel sheets. Experimental tests to determine the friction coefficient were carried out using the strip drawing method with the use of a specially designed tribological device. Lubrication conditions, normal force, and the surface roughness of countersample surfaces were used as input parameters. The friction tests were conducted in dry friction and lubricated conditions with three grades of oils with a wide range of viscosities. Different transfer functions and various training algorithms were tested to build the optimal structure of the artificial neural networks. An analytical equation based on the parameters that were being investigated was created to calculate the COF of each material. Different methods of partitioning weight were employed for the expected COF to assess the relative importance (RI) and individual feature’s relevance. A Shapley decision plot, which uses cumulative Shapley additive explanations (SHAP) values, was used to depict models for predicting COF. CatBoost was able to predict the coefficient of friction with R ^2 values between 0.9547 and 0.9693 as an average for the training and testing dataset, depending on the grade of steel sheet. When considering all the materials that were tested, it was discovered that the Levenberg–Marquardt training algorithm performed the best in predicting the coefficient of friction.
Design and Simulation of Oil Palm FFB Loading Machine
Desrial, K. Muhammad
The process of loading the fresh fruit bunches of oil palm to the truck requires a lot of manpower if it is done manually. In fact, either the palm oil plantation or the smallholder palm oil farmer still performs this task manually, so that it can lead to fatigue and can result in injuries for the worker due to heavy workload. The purpose of this research is to design and simulate a machine for lifting the fresh fruit bunches to the truck, so that the activities of lifting the fresh fruit bunches to the truck become easier and can have a bigger working capacity. This research was conducted using a functional and structural design approach consisting of several stages, including: problem identification, design concept formulation, engineering analysis, engineering drawings, material strength analysis, kinematics simulation, power consumption simulation, and digital scale simulation. A simple structure of electric motor-driven bucket elevator was designed to load the fresh fruit bunches on to the truck tailgate. Based on the simulation results, the fresh fruit bunches can be lifted up satisfactorily from the bottom to the top with an elevator mechanism. This elevator is designed with lightweight for easy installation and kept at the tailgate of the truck. The maximum electric power consumption for lifting the fresh fruit bunches was found to be 1466.24 watts with designed loading capacity 23 ton/hour.