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Recent developments in emissions regulations are pushing Non-Road Mobile Machineries manufacturers towards the adoption of more efficient solutions to reduce the amount of pollutants per unit of work performed. Electrification can be a reasonable alternative to traditional powertrain to achieve this goal. The higher complexity of working machines architectures requires, now more than ever, better design and testing methodologies to better integrate electric systems into mechanical and hydraulic layouts. In this work, the attention focused on the use of a Hardware in the Loop (HIL) approach to test performance of an energy management strategy (called load observer) developed specifically for an orchard tractor starting from field characterization. The HIL bench was designed to replicate a scaled architecture of a parallel hybrid electric tractor at mechanical and electrical level. The vehicle behavior was simulated with a personal computer connected on the CAN BUS network designed for the HIL system. Several tasks were simulated starting from data gathered during field measurements of a daily use of the machine. Results showed good performance in terms of load split between the two power sources and stability of the speed control although the variability of the applied load.

Contact problems as they occur in tribology and colloid science are often solved with the assumption of hard-wall and hard-disk repulsion between locally smooth surfaces. This approximation is certainly meaningful at sufficiently coarse scales. However, at small scales, thermal fluctuations can become relevant. In this study, we address the question how they render non-overlap constraints into finite-range repulsion. To this end, we derive a closed-form analytical expression for the potential of mean force between a hard wall and a thermally fluctuating, linearly elastic counterface. Theoretical results are validated with numerical simulations based on the Green's function molecular dynamics technique, which is generalized to include thermal noise while allowing for hard-wall interactions. Applications consist of the validation of our method for flat surfaces and the generalization of the Hertzian contact to finite temperature. In both cases, similar force-distance relationships are produced with effective potentials as with fully thermostatted simulations. Analytical expressions are identified that allow the thermal corrections to the Hertzian load-displacement relation to be accurately estimated. While these corrections are not necessarily small, they turn out surprisingly insensitive to the applied load.

Plant virus-like particles, and in particular, tobacco mosaic virus (TMV) particles, are increasingly being used in nano- and biotechnology as well as for biochemical sensing purposes as nanoscaffolds for the high-density immobilization of receptor molecules. The sensitive parameters of TMV-assisted biosensors depend, among others, on the density of adsorbed TMV particles on the sensor surface, which is affected by both the adsorption conditions and surface properties of the sensor. In this work, Ta2O5-gate field-effect capacitive sensors have been applied for the label-free electrical detection of TMV adsorption. The impact of the TMV concentration on both the sensor signal and the density of TMV particles adsorbed onto the Ta2O5-gate surface has been studied systematically by means of field-effect and scanning electron microscopy methods. In addition, the surface density of TMV particles loaded under different incubation times has been investigated. Finally, the field-effect sensor also demonstrates the label-free detection of penicillinase immobilization as model bioreceptor on TMV particles.

A three-phase induction motor is often used in everyday life because of its high reliability. However, it is associated with some disadvantages, including difficulties in maintaining constant speed during load changes and speed regulation due to the decoupled system. Therefore, this study aims to adjust the three-phase induction motor control to become a separate amplifier DC motor by setting the vector control using the IFOC method, which changes the coupled to the decoupled system. The speed settings are equipped with a PID controller where its parameters, which are obtained using Ziegler Nichols, produce speed output with fast research time and small steady-state errors. This research was conducted to observe and analyze the performance of a controller based on the IFOC approach with a PID controller at speed differences, with static and dynamic conditions in the entire speed working area. In the first stage of the research, simulation is carried out with static conditions, namely changes in speed variations throughout the work area (low speed to high speed), the next stage is a simulation with dynamic conditions, which is to provide changes in the value of the load torque when the system is operating. The simulation result carried out with LabVIEW shows a response time of 1.13 ms, a settling time of 9.9 ms, and a steady error of 0.4% at the 500 Rpm set point. It also indicated dynamic characteristics with a recovery time of 4.9 ms at the 300 Rpm set point. When operated at low speed, IFOC with PID controller has a stable response. But In dynamic conditions, the use of a PID controller is considered unsuitable. This is because the PID controller is less fast and less robust in responding to the system when conditions change in the value of the load torque.

This study aims to investigate the effect of rice husks’ particle size on resin-based brake pad performance (i.e. compressive strength, puncture strength, mass loss, wear rate, friction coefficient, and heat resistance). Bisphenol A-epichlorohydrin and cycloaliphatic amine were mixed to form resin and used as the brake pad's base material. In the experiment, rice husk with a specific particle size (i.e., 250, 500, dan 1000 μm) was added to the resin. Rice husk has received considerable interest due to its lignin, cellulose, and silica content, making it suitable as friction material due to its ceramic-like behavior. The experimental results showed small rice husk particles improved compressive strength, puncture strength, and bulk density. This can be obtained from the analysis of the maximum compressive strength for brake pad supported by particles with sizes of 250, 500, and 1000 μm having values of 0.238; 0.173; and 0.144 MPa, respectively. In contrast, large particles formed coarse surfaces and pores, decreased mass loss rate, and improve friction properties (i.e. wear rate, friction coefficient). The friction coefficient values of brake pad supported by particles with sizes of 250, 500, and 1000 µm were, respectively, 0.2075; 0.2070; and 0.3379. Particle size affected interpacking, interfacial bonding, pores number and size, thermal softening, mechanical properties, and friction properties of the brake pad. Comparison between the prepared resin-based and commercial brake pad was also done, confirming the utilization of agro-waste as a potential alternative for friction material in the brake pad.

Nano γAl2O3 has been one of the nanometal oxides that has improved the characteristics of biodiesel. The effect of γAl2O3 nanoparticles addition on premixed flame combustion is investigated with an experiment on the laminar flame speed of Calophyllum inophyllum methyl ester 30% and 70% petrodiesel mixtures, at atmospheric pressure and preheated temperature T = 473K. The γAl2O3 nanoparticles added to CIME30 biodiesel were 0ppm, 100ppm, 200ppm, and 300ppm. Experiments were carried out on a bunsen burner. The equivalent ratio of the mixture between ϕ = 0.67 to 1.17. Experiments revealed that the addition of nanoparticles to CIME30 biodiesel expands the flammability limit and increases the laminar flame speed. CIME30 without nanoparticles, flame stable between ϕ = 0,76 -1,17. CIME30 with nanoparticles, flame stable between ϕ = 0,67 -1,17. Combustion of CIME30 required a lot of air. The highest laminar flame speed occurred at the equivalent ratio ϕ = 0.83. The highest laminar flame speed of CIME30 0, 100, 200, and 300 ppm were 30.77, 34.50, 35.90, 38.45 cm/s respectively. The higher the nano γAl2O3 concentration the higher the laminar flame speed. This occurs due to the catalytic effect of γAl2O3 on biodiesel and its mixtures.

Municipal solid waste (MSW) is a type of general waste that includes households, traditional markets, commercial areas, and the rest from public facilities, schools, offices, roads, and so on. Refuse Derived Fuel (RDF) is obtained from the remnants of MSW which cannot be used anymore, which is flammable waste and is separated from parts that are difficult to burn through the process of chopping, sifting, and air classification. RDF has potential as an alternative energy source. In this study, RDF fuel was compared with MSW fuel both by proximate and calorific value, then the gasification process was carried out using a multi-stage downdraft gasifier to see gasification performance indicators such as syngas composition, LHV, cold gas efficiency, and tar concentration. The results showed that the gasification performance indicator for MSW biomass resulted in the syngas composition of CO = 19.08% v, H2 = 10.89% v, and CH4 = 1.54% v. The calorific value (Low Heating Value, LHV ) of syngas is 4,137 kJ/kg, cold gas efficiency is 70.14%, and tar content is 57.29 mg/Nm3. Meanwhile, RDF obtained the composition of CO gas: 18.68% v, H2: 9.5446% v, and CH4: 0% v. The maximum LHV syngas is 3365.08 kJ/kg, cold gas efficiency is 57.19 % and the smallest tar content is 80.24 mg/Nm3. When compared to RDF, MSW produces a better gasification performance indicator. However, RDF can still be used as an alternative energy source using the gasification process. The results of this study can be used to optimize the further RDF gasification process.

Bimetallic materials are construction materials that are increasingly used in many industries: in the graphic industry, tobacco processing industry for various cutting knives, in the chemical industry for various plants and vessels, food industry, military industry, etc. In the production of ships, their use becomes dominant, primarily as a combination of cheap construction materials highly resistant to corrosion, at a price closer to construction materials. The appearance of plating with the help of explosion energy has significantly increased the range and quality of available multilayer metals. Although stainless steels and aluminum are the most commonly used material for bimetallic and clad materials, materials such as titanium, zirconium or tantalum are increasingly used. The paper analyzes the process of explosion welding and the results of exploration of the explosion of a welded joint of copper and brass. The microhardness of the material in the welded joint, tribological characteristics and scratch test joint were analyzed.

The purpose of this paper was to investigate the wear rate and the temperature distribution of a single-layer TiN coated drill in H13 steel alloy workpiece, with the use of a numerical procedure and through relevant experiments. Simulation models were developed, and an experiment was conducted to evaluate the wear rate, as well as the wear mechanisms and the temperatures appeared during the process of drilling. The finite element method was used to simulate the drilling process. The Usui wear model was used for the drill’s wear rate estimation. Temperature measurements were carried out with a thermal imaging camera, and SEM microscopy was also used to characterize the coating’s wear. The maximum wear rate of the drill either of flat or for angled simulation setups is near . This value is obtained for maximum tool temperature, which in both cases is close to , however with different distribution within time. The comparative analysis of the simulation models and the experiment show that adhesion is the dominant wear mechanism and the values of the temperature are in good agreement ( difference) between the model and the measurements, even after the process temperature measurement. Because of the good chip evacuation and chip length the coated drills are suitable for drilling tough materials.

In the air, water vapor always exists and impacts directly on the friction surface between the piston rod and the rod seal. Water vapor in the air forms moisture film on the surface of the piston rod. In some cases, it plays a role as a lubricant. In general, to evaluate the amount of water vapor in the air, we use two measuring quantities that are relative humidity and absolute humidity. Although the relative humidity is equal at different temperatures, the amount of water vapor in the air is not the same and can be determined by absolute humidity. The paper presents the results of research on the effect of humid air temperature on the frictional behavior of the piston rod and a rod seal, under constant relative humidity conditions. The studies were conducted at a temperature of 150C, 320C, and 490C, with velocities of 5, 10, 30, 50, and 100 mm/s, respectively. The results show that the friction between the piston rod and rod seal (including a maximum force of static friction - FS and dynamic friction-FD) changes according to the ambient temperature of the humid air. When the temperature increases from 150C to 490C, the friction force decreases approximately 10 - 18%. The change in maximum force static friction is 1.2 times greater than dynamic friction force.

This paper presents a study on multi-objective optimization of turning process AISI 1055 steel. It designs 9 experiments (L9) for a Taguchi test series matrix. The four parameters of input include spindle speed, feed rate, depth of cut, tool nose radius. The AISI 1055 steel machining operation experiments are carried out based on the matrix created. They are performed on a conventional lathe. The factors considered for evaluating the machining quality include surface roughness, cutting force in X, Y, Z directions and material removal rate (MRR). First, the research is carried out to identify the impact of the input parameters on the output parameters. Analysis of experimental results show that spindle speed significantly affects all three components of cutting force, but slightly influences the surface roughness. Regarding feed rate, this is the parameter that has a strong effect on surface roughness and cutting force Fx but not on the cutting force Fy and Fz. Meanwhile, the depth of cut has a considerable influence on the force in the x and y directions but a limited impact on the surface roughness and the force in the z direction. Similar to the cutting speed, the tool nose radius is noticeable to all three components of the cutting force and negligible to surface roughness. The second aim of this study is to determine the value of the cutting parameters to achieve the minimum of surface roughness and cutting force and the maximum of MRR. The Data Envelopment Analysis-based Ranking (Dear) method is applied to solve multi-objective problems. The paper identified the optimum values of spindle speed, feed rate, depth of cut and tool nose radius are 910 rev/min, 0.194 mm/rev, 0.2 mm and 0.2 mm, respectively.

Wet-running multi-plate clutches fulfill a major safety-relevant role in drive trains and, as a result, damage to and failure of the clutch system must be strictly avoided, especially spontaneous damage. This paper deals with spontaneous damage to wet-running multi-plate clutches with paper friction lining with respect to spontaneous damage behavior. The paper presents a comparison method, by means of which the load-carrying capacity of various multi-plate clutches can be compared with regard to spontaneous damage based on experimental data and recommendations can be formulated. The experiments were performed on six different clutch variants, and the results were examined for significant differences. Various statistical tools were used to detect statistically significant variations. The experiments showed that higher load levels have a greater dispersion of the measured values, thus making comparisons more difficult. In the clutch variants investigated, significant changes in spontaneous damage behavior could only be detected when the cooling plate thickness or the carbon content was changed.

Vegetable oils have been acknowledged to have significant potential as a substitute base fluid in grease formulation. The so-called biogreases are demanded especially in open applications where the greases are in contact with soil and water and lost to the environment. In this paper, formulation of a biogrease derived from palm-based ester as the base fluid and calcium complex soap as the thickener is discussed, with the main purpose to explore the potential of palm oil as an effective biodegradable fluid, and to investigate the possibility to improve the tribological properties by mixing calcium carbonate (CaCO3) and hydroxyapatite (HA) as green additives. The wear and friction properties as well as the load carrying capacity of the formulated bio-grease were extensively studied through the four-ball wear tester. The experimental results show that the average coefficient of friction of the palm based biogrease was improved by about 6.5% when 5% of CaCO3 and 3% of HA were added comparing to base grease. Besides, the load carrying capacity was also enhanced significantly by the addition of the additives. This demonstrated the good potential of palm ester as base fluid for grease and the CaCO3 and HA as lubricant additives, exhibited the good anti-friction and load carrying abilities.

An experimental-calculation procedure for determining the kinetic and energy activation criteria for assessing the wear resistance and compatibility of triboconjunction materials using the kinetic three-stage triboreaction is presented. The developed method for tribo-kinetic tests to determine the kinetic characteristics (order and rate constants) and activation energies for all three stages of the triboreaction was tried experimentally for steels ShKh-15 and 45, aviation fuel RT, aviation hydraulic oil AOH-10 and aviation oil MK-8 added with oleic acid. The conducted tribo-kinetic tests established kinetic and activation energy criteria for assessing the wear resistance of ShKh-15 steel and antiwear properties of RT and AOH-10 lubricants, as well as kinetic criteria for assessing the wear resistance of steel 45 and antiwear properties of MK-8 with oleic acid. Also, using the developed method for tribokinetic tests, the kinetic and activation energies of ShKh-15 in long-term storage aviation fuels “TS-1” and “TS-1*”, kinetic criteria and activation energy for the second stage of the triboreaction, chemical modification ShKh-15 in the medium of "TS-1", as well as the established kinetic and activation energy of the triboreaction, that is, surface destruction, in fact, wear of steel 45 during reciprocating motion.

Multilayer coatings [Si3N4/Al2O3]n have generated great interest due to their intriguing properties which have made them a potential candidate to be implemented in different processes within the food and pharmaceutical industries. Unfortunately, this multilayer system based on [Si3N4/Al2O3]n does not have strong tribological studies that could express in an emphatic way its own tribological characteristics. For this reason, the aim of this research consisted of a detailed study of the evolution of the mechanical and tribological properties of the [Si3N4/Al2O3]n coatings as a function of the bilayer number n=1, 10, 30 and 70, with special emphasis on the tribological analysis in a dry and lubricated environment. It was determined that the mechanical properties such as the hardness and the elastic modulus increased by 29% and 6.3%, while the friction coefficient in a dry and lubricated environment decreased by 33% and 81.8%, respectively, when increasing the bilayers from n=1 to n=70. Thus, the present study determined that the coating [Si3N4/Al2O3]70 presented ideal properties that make it a promising candidate to be implemented as a protective coating on processing devices within the food and pharmaceutical industry.

Using a segmented grinding wheel improves chip release and heat release condition out of the cutting zone, facilitates the introduction of coolant into the cutting zone, as well as increases the ability to clean the grinding wheel surface. Therefore, using segmented grinding wheel promises to improve the quality and efficiency of the machining process. This paper presents a study about the multi-objective optimization of grinding process using a segmented grinding wheel. The parameters that are shosen as the output criteria are the surface roughness, amplitudes of system vibrations in X, Y, Z directions (Ax, Ay, Az), and the material removal rate (MRR). The experiments were performed in the surface grinding machine with the workpiece material of DIN 1.2379 steel and the grinding wheel material of aluminum oxide. The experimental matrix was designed using Taguchi method with nine experiment (orthogonal array L9) and with four input parameters (number of grooves, workpiece velocity, feed rate, and depth of cut). From the experimental data, the influence of input parameters on the output parameters were investigated. The TOPSIS method was applied to solve the multi-objective optimization problem. Then, the optimized set of input parameters was determined to ensure the minimum value of surface roughess, minimum values of three vibarion components, and to ensure the maximum value of MRR. Finally, the future research directions of this study were also proposed.

The desulphurization process of diesel fuel is carried out to reduce the amount of SO2 emissions that can cause acid rain. However, the desulphurization process in diesel fuel not only removes the sulfur compounds but polyaromatic and polar compounds are also eliminated during this process. The loss of these two compounds can reduce the lubricity properties of diesel fuel. Therefore, it is necessary to add an additive compound that can increase the lubricity properties. In this research, 2-hydroxyethyl ester (HEE) was synthesized as an additive to increase the lubricity of diesel fuel. This compound was synthesized through the transesterification reaction of soybean oil and ethylene glycol with K2CO3 as the base catalyst. The composition of the synthesized additives was analyzed using the Gas Chromatography-Mass Spectrometry (GC-MS). Based on the results of GC-MS spectrum analysis, it is known that the 2-hydroxyethyl ester compound has been formed with a yield of 66.5% (relative to the area of the chromatogram peak). The HEE compound obtained is a mixture of 2 hydroxyethyl palmitate, 2 hydroxyethyl linoleate, 2 hydroxyethyl stearate, 2 hydroxyethyl arachidonate, 2 hydroxyethyl nervate, and 2 hydroxyethyl behenate.

This study relates to research on improving analytical models of gears. A new analytical model of gear shaft with 5 DOF is proposed. Equations of vibration are derived without small-angle approximation and are presented in a form that could be implemented in Simulink. To determine the effect of the additional DOF, four popular models having 2 DOF, 4 DOF, 6 DOF and 8 DOF are investigated, too. The proposed model has 12 DOF in total. This number of DOF could be increased; this, however, would result in a greater difference between the considered models, thus making it more difficult to evaluate the impact of the additional DOF of shafts. As a benchmark, the dynamic meshing force in the considered analytical models is calculated. Simulations are carried out with and without friction. Additionally, for the 12 DOF model, the effects of the position of the centre of gear and the centre of mass are investigated.

Self-piercing riveting (SPR) has been widely used in automobile industry, and the strength prediction of SPR joints always attracts the attention of researchers. In this work, a prediction method of the cross-tension strength of SPR joints was proposed on the basis of finite element (FE) simulation and extreme gradient boosting decision tree (XGBoost) algorithm. An FE model of SPR process was established to simulate the plastic deformations of rivet and substrate materials and verified in terms of cross-sectional dimensions of SPR joints. The residual mechanical field from SPR process simulation was imported into a 2D FE model for the cross-tension testing simulation of SPR joints, and cross-tension strengths from FE simulation show a good consistence with the experiment result. Based on the verified FE model, the mechanical properties and thickness of substrate materials were varied and then used for FE simulation to obtain cross-tension strengths of a number of SPR joints, which were used to train the regression model based on the XGBoost algorithm in order to achieve prediction for cross-tension strength of SPR joints. Results show that the cross-tension strengths of SPR steel/aluminum joints could be successfully predicted by the XGBoost regression model with a respective error less than 7.6% compared to experimental values.

Composite is a material that consisting of two or more materials, either micro or macro, where the properties of the material differ in shape and chemical composition from the original substance. In this study, fatigue testing of fiber metal composites was carried out to determine the rate of crack propagation so that the age of the fiber metal composite specimen was known. The independent variable in this research is the angular orientation of the carbon fiber and the surface roughness of the aluminum with the dependent variable response is the bridge crack rate. The manufacture of fiber metal laminates specimens uses the Vacuum Resin Infuse (VARI) method, which uses a vacuum pump as a means to flow the resin from the reservoir to the mold. This method is used to minimize the occurrence of air bubbles trapped on the specimen which causes porosity defects which will reduce the strength of the metal laminates specimen itself. Fatigue testing is performed using the stress amplitude method. That is, the value of the load when the tensile test is one third of the tensile strength. After the fatigue test was carried out, the results were obtained on specimens with an angular orientation of 0/90 ° fibers, the crack propagation rate slowed down with a cycle value of 90000 in specimens with a surface roughness value of 2.128 µm then decreased cycles on specimens with a value of 2.887 µm, namely 11000 cycles.

The noncircular synchronous belt drive mechanism has demonstrated certain achievements and has been used in special fields. Research regarding noncircular synchronous belt drive mechanisms has focused on optimization design and kinematic analysis in China, whereas two pulley noncircular synchronous belt transmissions have been developed overseas. However, owing to the noncircular characteristics of the belt pulley, the real-time variation in the belt length slack during the transmission of the noncircular synchronous belt is significant, resulting in high probabilities of skipping and vibration. In this study, a noncircular tensioning pulley is added to create a stable three-pulley noncircular synchronous belt driving mechanism and a good synchronous belt tensioning, with no skipping; hence, the non-uniform output characteristic of the driven pulley is consistent with the theoretical value. In the circular noncircular noncircular three-pulley noncircular synchronous belt mechanism, the pitch curve of the driving synchronous belt pulley is circular, whereas those of the driven synchronous belt and tensioning pulleys are noncircular. To minimize the slack of the belt length of the synchronous belt and the constraint of the concavity and circumference of the tensioning pulley, an automatic optimization model of the tensioning pulley pitch curve is established. The motion simulation, analysis, and optimization code for a three-belt-pulley noncircular synchronous belt drive mechanism is written, and the variation in belt length slack under different speed ratios is analyzed based on several examples. The testbed for a circular–noncircular–noncircular three-pulley noncircular synchronous belt transmission mechanism is developed. The test shows that the three-pulley noncircular synchronous belt drives well. This study proposes an automatic optimization algorithm for the tensioning pulley pitch curve of a noncircular synchronous belt transmission mechanism; it yields a stable transmission of the noncircular synchronous belt transmission mechanism as well as non-uniform output characteristics.

Vibration analysis is generally used in the industries for condition monitoring of various electromechanical equipment. For the predictive maintenance of the industry equipment, several techniques have been applied which are based on capacitive and piezoelectric accelerometers. However, they possess several real time problems due to the negative influence of electromagnetic interference. The major problem lies in the detection and transmission of various physical parameters in the noisy and harsh environment. In order to solve the weak points of commonly used structural vibration detection sensors that are easily affected by the harsh environment of the engineering site, the principle of optical fiber sensing is studied, and the system optical path is designed based on MZ interference technology. In this work, a special data acquisition and processing software is developed to acquire the sensed data and the vibration detection is carried out on the steel cantilever structure pasted with fiber optic sensors. Extraction using FFT and pattern recognition through bp neural network yields the system accuracy rate of 96.7 %. The proposed interference type optical fiber technology provides a novel approach for real-time monitoring of engineering structure vibration laying the foundation for the research of intelligent buildings.

Fine-grinding is a final machining method used to reach the low friction and high-quality surface. The workspeed (vw) and crossfeed (vc) motions are perpendicular to each other and differ in value during the grinding process. Thus, the surface quality in workspeed and crossfeed direction is not the same and leads to the anisotropy of friction in the working surface. This paper presents the results of the study on the direct effect of grinding parameters on anisotropic surface friction of AISI 1045 Steel. The research was performed on the UCETR- UMT multifunctional test system, and the experimental samples were ground under the workspeed of 15,4; 19.2, and 23 m/min, respectively, and crossfeed of 0.3 m/min. The research results show that the experimental coefficient is 7 to 17% larger than the calculated friction coefficient. The experimental friction force consists of 2 components: Fx is friction force according to the measuring motion direction, Fy is the perpendicular anisotropic friction force Fx. Total friction (Fx+Fy) changes 8-18% in the workspeed direction and 15-23% in the crossfeed direction in the experimental region. The value of the anisotropic friction force Fy varied from 0.78% to 41% compared to Fx. Therefore, the anisotropy friction can be expressed by the angle αani=arctg Fy/Fx, which depends on the direction of motion during the grinding and the grinding parameters.

Long robotic arms are useful for many applications such as nuclear plant decommissioning, inspection, and firefighting. A major problem for designing and operating long robotic arms is that even small end effector reaction forces and arm gravity can result in large loads on proximal arm joints because of long moment arms. To solve that problem, previous researches focus on specifically designed long arms with certain compensation mechanisms. However, those specialized arm designs are difficult to be applied to existing long robotic arms and to be customized for different missions. To overcome those two drawbacks, we recently proposed a watch-like thrust-generating modular device, called flying watch, with the following two major advantages. Firstly, flying watch can be attached to different kinds of existing long robotic arms and generate thrusts to enhance arm strength. And we have proposed a thrust planning method for flying watch in our previous work. Secondly, since different flying watch attachment allocations can enhance the same robotic arm in different ways, flying watch attachment allocations can be customized to meet the needs of a specific mission. However, up to now, customizing flying watch attachment allocations to different missions is still based on human experience and there is no clear performance metric and automated design method for flying watch attachment allocation. To facilitate mission-dependent long arm enhancement, in this paper, we first propose a novel performance metric, called thrust drivability, which measures the ability of a flying watch attachment allocation to counteract unexpected end effector reaction forces. Then based on thrust drivability, we propose an automated design method, called Allocation Optimization based on Weighted Situations (AOWS), for generating mission-dependent flying watch attachment allocations counteracting both unexpected and known external forces. Simulations show that AOWS based allocation designs can counteract both known and unexpected external forces much better than human-experience-based allocation designs.

Nowadays, there are several important reasons for using high-strength sheets in the manufacture of car bodies. Car manufacturers choose the steel with good formability, fatigue resistance and ability to absorb impact energy. One of these materials, which fulfil above mentioned criteria are microalloyed steels and dual-phase steels. The application of high-strength sheets has led to develop new materials joining techniques. Mechanical joining such as clinching is the innovative technique to join these progressive materials. Materials of different thicknesses can be joined by clinching. The paper focuses on the comparison of the properties of the joints made by clinching and resistance spot welding. The application of resistance spot welding is still the most used joining method in car body production. These properties were investigated by tensile test and metallographic observation. Steel sheets HCT600X+ZF, HCT600X+Z and HX420LAD+Z were used for the experiments. The results of tensile test show that the values of load-bearing capacity of clinched joints reached from 3900 N to 5900 N and resistance spot welded joints reached the values of load-bearing capacity from 12000 N to 19500 N. In comparison to the resistance spot welded joints, the clinched joints reached from 32 to 48% of load-bearing capacity.

The article presents the methodology of tribological and rheological research of typical lubricating composition. The analysis of friction factor, friction work, frictional force, frictional power values during the test for the tested lubricating composition indicates a significant change in this parameters for lubricants. A change of the value of evaluated tribological parameters leads to a change in the structure of the composition carried out tests and a change in the effectiveness of the tribological protection of the tribosystem. The content of the thickener, base of oil and additive in the lubricant structure affects the level of the anti-wear properties, as evidenced by the results obtained during the tribological tests presented in this article. The DWS (Diffusing Wave Spectroscopy) technique provides the ability to obtain information about the viscoelastic state of non-Newtonian liquids and provide the monitoring of structural changes in time. The observation of the movement of the dispersed phase particles and the evaluation of the microstructure change in the solutions based on the results of the correlation function MSD (Mean Square Displacement) in time, complex viscosity, complex modulus and the research of the G 'and G” modulus in wide frequency range provides a comprehensive microstructure characteristic of the tested systems at the microscopic level.

The inconsistency of the wind flow considered as one of the factors which tend to decrease the performance of the wind turbine. This paper proposes a further analysis of the initial rotation characteristic of a hybrid Savonius - Darrieus wind turbine. The addition of the Darrieus blade intends to increase the aerodynamic stability of the overlapping Savonius turbine. This study implements 2D CFD transient analysis using the 6DOF methods in 00, 300, 600, and 900 Darrieus blade position along with 2 m/s, 4 m/s, and 6 m/s wind speed variations. The results of the aerodynamic analysis show that the location of the Darrieus 300 turbine provides the greatest initial repulsion, especially when the turbine rotation is above 900, the position of the Darrieus blade can provide additional impulse force when the Savonius turbine tends to be passive. This effect occurs more significant at higher wind speeds. Savonius with 3-blade modification has a more stable level of force distribution than the 2-blade modification, although the value is smaller. This shows that the 3-blade Savonius provide a higher stability of angular velocity development.

This work aimed to study the microstructure, wear and corrosion resistance of supermartensitic stainless steel (SMSS). Heat treatment applied to samples consists of quenching after austenitization at elevated temperature (1250 °C) followed by a double tempering at 650 °C. Conventional mechanical properties, scanning electron microscopy (SEM/EDS) analysis and X-ray diffraction methods (XRD) are used to analyze the microstructure and to evaluate the wear mechanisms. The potentiodynamic polarisation and the electrochemical impedance spectroscoopy (EIS) methods are used to evaluate the corrosion resistance in both the 0.5M H2SO4 and 0.5M NaCl aggressive media. The microstructure is mainly composed with tempered lath martensite, small quantity of retained austenite and carbides. Oxidative and abrasive wear dominated the wear process in dry condition. During the corrosion process, the same mechanism of degradation was found in both the 0.5M NaCl and 0.5M H2SO4.

Phenomena accompanying the self-ignition period have been and are the subject of extensive research in this area. They are usually carried out in constant volume pressure chambers or in reactors with constant air flow. Such tests are considered to be basic tests. The conditions in these tests are definitely different from those in compression-ignition engines. Therefore, the comparison of the auto-ignition delay periods from test stands to those obtained from real engines raises a number of doubts. Because the self-ignition delay period determines the combustion process, I made a theoretical analysis of a number of factors that have an impact on this process which determines the operational aspects of the engine, and thus its economics and ecology. The research object was a single-cylinder engine from the AVL LIST GmbH in Graz, Austria. The engine is equipped with Common Rail injection system. The test stand meets the standards: Directive 1999/96/EC of the European Parliament and the Council of 13th December 1999, Regulation (EC) No 715/2007 of the European Parliament and the Council of 20th June 2007, as well as Commission Regulation (EC) No692 /2008 of 18th July 2008. The analysis of the operational aspects of the self-ignition delay period was based on the results of tests on the AVL 5402 engine when fed with hydrocarbon fuels: diesel and synthetic oil. The engine was also fed with vegetable fuel - rapeseed oil. The obtained material from the tests warns the user of CI engines against the effects of their failure if the engine control parameters and the quality of fuel for its supply are not maintained as recommended by the manufacturers. The material contained in the publication is used for scientific analysis, and, which is worth emphasizing, is of a utilitarian nature.

Natural fiber reinforced composites is one materials potentially developing in Indonesia. One of biggest problem with composites specimen is its void. One properties to find out void of composites is composites density value. The objective of research is to investigate the effect of fiber alkali (NaOH) treatment and microcrystalline cellulose (MCC) addition on density value of cantala fiber reinforced unsaturated polyester composites. Firstly, cantala fibers was submerged into alkali (NaOH) 6% solution for 0, 3, 6, 9, and 12 hours. Furthermore, the fiber was washed using acetid acid and then using clean water to reach pH 7. Thereafter, cantala fiber was dried in the oven for 10 hours at temperature 600C. Composites was composed of cantala fiber, unsaturated polyester polymer matrix, and microcrystalline cellulose according to the composition with volume fraction 30%. Composites was casted using compression molding method with compressive strength of 10 MPa for 12 hours. All specimens of composites undertake post cure for 2 hours at 600C. Density test was conducted using densimeter by calculating the density of composites in the air and the water. The result of research showed that the longer the alkali treatment time and the more addition of microcrystalline cellulose (MCC) filler, the higher is the composites density. The higher density value of cantala fiber reinforced unsaturated polyester is alkali treatment 6 hours, which was 1.223 gr/cm3.

The KOBO extrusion is an unconventional elastic-plastic deformation process in which the phenomenon of changing a path of plastic deformation due to die cyclic oscillations by a given angle and with a given frequency is applied. As the results of the application of the oscillating rotary motion of the die, the reduction of the extrusion force is obtained. The numerical study of the KOBO extrusion of metallic materials is presented in this paper. The three-dimensional coupled Eulerian-Lagrangian (CEL) analysis is applied here. The relationship between the extrusion force and the punch displacement during the KOBO process was achieved. The effective plastic strain distribution in the butt was found. The results of the numerical computations are compared with the experimental data. The influence of the material hardening parameters on the cyclic loading phenomena (ratcheting, mean stress relaxation) in terms of the course of the KOBO extrusion was also examined. The proper determination of the material hardening parameters can help to optimize the KOBO process in terms of the reduction the extrusion force and the choice of the amount of die oscillations.

This paper presents an EKF-based self-attitude estimation with a DNN (deep neural network) learning landscape information. The method integrates gyroscopic angular velocity and DNN inference in the EKF. The DNN predicts a gravity vector in a camera frame. The input of the network is a camera image, the outputs are a mean vector and a covariance matrix of the gravity. It is trained and validated with a dataset of images and corresponded gravity vectors. The dataset is collected in a flight simulator because we can easily obtain various gravity vectors, although the method is not only for UAVs. Using a simulator breaks the limitation of amount of collecting data with ground truth. The validation shows the network can predict the gravity vector from only a single shot image. It also shows that the covariance matrix expresses the uncertainty of the inference. The covariance matrix is used for integrating the inference in the EKF. Flight data of a drone is also recorded in the simulator, and the EKF-based method is tested with it. It shows the method suppresses accumulative error by integrating the network outputs.

This article presents an experimental research in the grinding the 65G steel. The workpiece velocity, feed rate, and cutting depth are selected as the input parameters for each experiment. The experiments were performed according to a Box-Behnken matrix consisting of 15 experiments. ANOVA analysis results have determined the influence of the input parameters and the interaction between them on the surface roughness. A surface roughness model in the form of quadratic polynomial was constructed. Two data transformations including Box-Cox and Johnson were applied to construct two new surface roughness models. The comparison of three surface roughness models was conducted. The comparison results show that the model using the Johnson transformation has the highest accuracy, the model using the Box-Cox transformation has the accuracy ranked the second position and the model without data transformation had the lowest accuracy.

The operation of dust suppressor and dust collector was operating semi-manually by pressing the power button on the local panel during the initial unloading of coal material from the barge or stockpile, where local operators manage several large areas. This research is carried out on the implementation of Automatic Dust Detector for Dust Suppression operational at Paiton Unit 9 power plants with the aim of increasing the efficiency of operator and equipment performance. We use House of Quality (HOQ) as a determinant of the priority scale for technical response to be implemented, namely the addition of an Automatic Dust Detector. The results obtained showed a decrease in the calculation of the dust suppression operating time, i.e. from 5 hour 54 minutes to 5 hour 6 minutes, from 1005,36L/barge to 869,04L/barge for water consumption, and 1L/barge to 0,86L/barge for chemical use. Furthermore, the implementation of the Automatic Dust Detector can significantly increase efficiency at least 15% from operating time difference.

The article presents the models of technological systems and the parameters of the control object allowing one to seek rational control algorithms, the choice of structure of the control system and synthesis of correction devices. The generalized and detailed structural schemes of controlling the elastic-deformable state during working on low-rigidity shafts while applying the tensile force as well as with additional feedback and transfer functions of technological systems, considering the assumptions made and the results of theoretical and experimental testing. The structure of the control object and the dependencies describing the system and considering the specificity of forming the section of the machined surface of the elastic-deformable low-rigidity shafts at longitudinal feeds. As a result of the research a method of increasing the accuracy of controlling the parameters of dynamic systems at the change of the longitudinal feed and regulating the parameters of the elastic-deformable state of low-rigidity elements by introducing correction devices in form of negative feedback in accordance with the cutting force. Moreover, the possibility of creating adaptive units which are not very sensitive to the change of parameters in turning and grinding.

Metal matrix composite (MMC) are composite materials that are widely used in the industrial sector. Examples of metal matrix composites are Al6061 as matrix alloys and Al2O3 as reinforcement. In general, making Al6061-Al2O3 composites using the stir casting method. The stirring parameter in the stir casting affects the physical and mechanical properties of the composites. The physical and mechanical properties of composites can be improved by increasing the wettability of the reinforcement. This research was conducted to determine the effect of the depth of stirring and electroless coating treatment on the hardness and tensile strength of Al6061-Al2O3 composites. The process of making composites with Al2O3 reinforcing particles with 6% weight fraction mixed with aluminum alloys and 2.5% magnesium powder as a wetting agent. Variations of this study were the depth of the stirrer and electroless coating treatment. The depths of stirring used for the experiment were 30%, 45%, and 60% of the height of the fluid. The testing phases in this study were the density and porosity test, metallographic observation, hardness test, and tensile test. The most efficient variation of the mixer depth was obtained at a mixer depth of 30% of the fluid height. The highest hardness and tensile strength test results are hardness value of 72.43 HBN and tensile strength of 182.19 MPa with electroless coating reinforcement treatment

Cylinder pressure vessel is a device that is used to process industry, power industry, oil industry, and gas industry. Structure of pressure vessel has complex design that is used to accommodate force, temperature, internal pressure loading, etc. Pressure vessel loading is supported by two saddle. Loading pressure vessel is distributed to saddle as stress. Stress distribution can be checked by finite element software. Autodesk Inventor 2019 is a software that used finite element basic. This research aims to get the effect of pressure vessel saddle width to maximum stress at pressure vessel.

Conventional machining of nickel-titanium shape-memory alloys (NiTi SMAs) faces significant challenges as a result of high thermal and mechanical distortions. The phase transformation temperatures of NiTi SMAs are primarily affected by the rise in temperature during the cutting process, which causes poor machinability under the conventional coolant approach. This research explored the effects of hybrid cooling- lubricating of minimal quantity nano-lubricants with compressible-chilled air generated from a vortex tube during the turning of the NiTi alloys. The experimental procedure involved measurement of induced-cutting force components under variable cutting conditions utilising various coolant approaches. A depth of cut, 0.5 mm with cutting speeds of 12.5, 25, and 50 m/min and feed rates of 0.05 and 0.1 rev/min were utilised. The hybrid cooling approach of minimum quantity nano-lubricants with vortex cooling, can increase tool life for most of the tested conditions and has a considerable influence in reducing the induced-cutting force. In contrast, only marginal improvement was observed for the surface roughness when using the same coolant-lubricant strategy.

A mathematical module for predicting and analyzing the drawing force is formed and verified. The process used in the current study is drawing. Geometric parameters of the deformation zone and the “selective transfer phenomenon” are also taken into consideration. The experimental verification is conducted through two tests: In the first test, the experimental blanks are cylindrical rods (steel 45, length 150 mm), and are preliminary machined by turning, and the drawplate made of steel 9xc, are used. Regular micro-relief (RMR) hardens the working surfaces of the drawplate. In the second test, the same conditions are applied except for the samples, which represent solid cylindrical billets made of steel 45 with a complicatedly modified surface layer, including a brass film, regular microgeometry, and a “servo-witte” copper film. As a result, in the first experiment, the discrepancies are in the range of -29.1% up to +23%. In the second experiment, the discrepancies are in the range of +1.38% up to +48.9%.

This article presents the structural health analysis of a full-scale vehicular bridge, using a twin model calibrated with experimental information. This structure consists of concrete arches, built more than 80 years ago, and reinforced in the 1990s with a steel structure. Different load combinations were evaluated in this model to determine the strength of the structure according to current design standards. Finally, it was found that several of its components do not meet the current design requirements, putting the structure in a vulnerable condition to seismic hazards and restricting its service to traffic loads.

This paper reports the use of External Magnetic Field-Tungsten Inert Gas (EMF-TIG) method in butt joint applications to determine the effect of welding arc compression on the quality of butt joint of SS 304 thin plate was reported. The welding process was performed without using filler or autogenous welds. The external magnetic field was generated by placing a magnetic solenoid around the TIG welding torch. The results of this study showed that EMF-TIG welding can produce a more uniform bead width along the weld line compare with conventional TIG. Moreover, the D/W ratio obtained under external magnetic field was higher than without magnetic. However, the tensile strength of butt joint decreased with EMF-TIG because there is constriction in arc welding which produces shrinkage weld pool volume. In addition, high welding speeds result in a decrease in the tensile strength of both conventional TIG and EMF-TIG welds.

Aiming at the problem that traditional fast spectral correlation (Fast-SC) cannot effectively extract the fault feature of rolling bearings under strong background noise, we propose to select a band with abundant fault information on the spectral frequency axis by Spectral Gini Index (SGI) and integrate over them to obtain the Improved Enhanced Envelope Spectrum (IEES). The proposed method doesn’t rely on the selection of precise fault characteristic frequency, and has a good industrial application prospect. The simulated and experimental results of rolling bearings prove the effectiveness of the algorithm.

In this study, a humanoid prototype of 2-DOF (degrees of freedom) lower limb exoskeleton is introduced to evaluate the wearable comfortable effect between person and exoskeleton. To improve the detection accuracy of the human-robot interaction torque, a BPNN (backpropagation neural networks) is proposed to estimate this interaction force and to compensate for the measurement error of the 3D-force/torque sensor. Meanwhile, the backstepping controller is designed to realize the exoskeleton's passive position control, which means that the person passively adapts to the exoskeleton. On the other hand, a variable admittance controller is used to implement the exoskeleton's active follow-up control, which means that the person's motion is motivated by his/her intention and the exoskeleton control tries best to improve the human-robot wearable comfortable performance. To improve the wearable comfortable effect, serval regular gait tasks with different admittance parameters and step frequencies are statistically performed to obtain the optimal admittance control parameters. Finally, the BPNN compensation algorithm and two controllers are verified by the experimental exoskeleton prototype with human-robot cooperative motion.

Ration card is an important government document used for the purchase of subsidized food grains by most of the households in India. But this system has two major drawbacks A) Inaccurate quantity measurement of food grains caused by human errors or by intentional use of inaccurate weights.B) High probability of fraudulent sale in the market in case of partial consumption of food grains allotted every month. To make the process more streamline and transparent, a Smart Card Based Public Distribution System using RFID (Radio Frequency Identification)technology is proposed.

Few physical models of oral and laryngeal systems for human speech movement exist for computer or mechanical simulators. In particular, a robot tongue mechanism that fully reproduces the deformation motion of the human tongue is lacking. The human tongue is an aggregate of muscles that is devoid of a skeleton. It possesses only a small hyoid. A mechanism that can drive and control the deformation of a soft body, such as the human tongue, along multiple degrees of freedom has not been realized to date. To solve this problem, a wire-pulling mechanism with embedded soft tubes is proposed. Using this mechanism, a flexible tongue that can be deformed along multiple degrees of freedom without breaking the wire is achieved. A prototype planar mechanism with two degrees of freedom that is capable of contraction and bending was fabricated. A deformation model that assumes a piecewise constant curvature (PCC) was formulated. Deformation tests confirmed that the prototype is capable of contraction and bending movements that are consistent with those of the model. Variations in the error with respect to the hardness of the deformable part are discussed, and the limits of the deformation model based on the PCC assumption are presented.

Electrical power system is changing from utility centric to customer centric after introduction of Electricity Act 2003 in India and unbundling of power sector in rest of the world. After unbundling, customer satisfaction has prime importance.Customer expectspower supply 24x7, which can be assuredonly after performingthe reliability analysis of generation system. The purpose of this paper is to present Neural Network (NN) approach, which can overcome limitationsof the conventionalreliability evaluation method such as poor accuracy, complicated models,and large timefor execution. This paper presents anorganized approach forestablishing the learning model with supervision using radial basis function neural network (RBFNN). This model is used for evaluation of various reliabilityindicesused for generation planning. Markov process and basic probabilistic approach is used to develop theinput-output training patterns for neural network. These patterns are normalized and presented to RBFNN. The validation of the proposed technique is confirmed by analyzingRoy Billinton Test System (RBTS) and IEEE-Reliability Test system (IEEE-RTS).

Direct Yaw Moment Control (DYC) is an effective way to alter the behaviour of electric cars with independent drives. Controlling the torque applied to each wheel can improve the handling performance of a vehicle making it safer and faster on a race track. The state-of-the-art literature covers the comparison of various controllers (PID, LPV, LQR, SMC, etc.) using ISO manoeuvres. However, a more advanced comparison of the important characteristics of the controllers’ performance is lacking, such as the robustness of the controllers under changes in the vehicle model, steering behaviour, use of the friction circle, and, ultimately, lap time on a track. In this study, we have compared the controllers according to some of the aforementioned parameters on a modelled race car. Interestingly, best lap times are not provided by perfect neutral or close-to-neutral behaviour of the vehicle, but rather by allowing certain deviations from the target yaw rate. In addition, a modified Proportional Integral Derivative (PID) controller showed that its performance is comparable to other more complex control techniques such as Model Predictive Control (MPC).

In this article, we constructa familyofclosed form traveling wave solutions to thespace-time fractional Equal Width equation(EW)and the space-timefractionalmodified Equal Width equation(mEW)by usingnewlyproposed modified rational fractional (𝐷𝜉𝛼𝐺/𝐺2)-expansion method and the exp-function method. The considered equations are turned into fractional order ordinary differential equations with the help of a complex fractional transformation along with conformable fractional derivative and then the methods are used to investigate their solutions. The achievedsolutions are in terms of trigonometric function, hyperbolic function and rational function which might be used to analyze deeply the physical complex phenomena of real world as they are new and bear much more generality.Two more well-established methods, the (𝐺′/𝐺)-expansion method and the rational (𝐺′/𝐺)-expansion method,are also taken into account to unravel the suggested equationswhich donot provide any solution.The resultsreveal thatthe proposedmethod is efficient, straightforward and concise whichmight further beuseful toolto examine any other nonlinear evolution equations of fractional orderarising in various physical problems.

Probabilistic localization based on Bayesian theory has been researched as a sensor fusion method to improve the robustness of localization. Pieces of position information, generated by sensors’ observation models with consideration for noises, are fused according to Bayesian theory. However, having large noises not considered in their observation models, the sensors output erroneous position information; thus, the fusion result has a significant error, even when the other sensors output correct ones. In this research, we have proposed a sensor fusion system with a relative correlation checking test to realize robust localization. Pieces of erroneous position information, biased against others and having a negative correlation with others, are detected and excluded in our proposed system by checking their correlation between all of them. The purpose of this paper is to evaluate the robustness of our fusion system by conducting recursive localization experiments in various environments.

In order to study the relationship between the transformer vibration and the operation state, the wavelet analysis method and the convolutional neural network method were used to analyze the transformer vibration signal. This paper proposes a transformer based on convolution neural network-based surface vibration signal feature extraction method. The result show that the convolution of neural network in different station transformer surface vibration signal classification has a lot of advantage, as the integration of feature extraction and classification recognition process together can effectively classify vibration signal recognition processing. This method is feasible for classification and identification by providing an accuracy value of 92.74 %. The future perspective of this research will focus on a generalized network model and parameters through experimentation for further investigation of accuracy and efficiency of this method.