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Electric motorcycles produce less vibration and noise than vehicles with internal combustion engines. However, the cogging torque of electric motors can cause vibrations, particularly at low speeds. When push-walking a motorcycle at very low speeds, this cogging torque produces handlebar vibrations, resulting in discomfort for the rider. Since motorcycles are typically turned off during push-walking, it is impossible to reduce these vibrations through motor control. Thus, reducing handlebar vibrations through motor cogging torque design is required. To simulate vibration, a detailed and large-scale model that considers the characteristics of drivetrain components like belts and gears, is required. Consequently, the optimization of vibrations in the early stages of design is challenging. The ultimate goal of this study is to construct a simulation model that can predict handlebar vibration during push-walking. This report investigates the vibration transmission mechanism. Vehicle
Okamura, TsubasaOtaki, RyotaSugaya, AtsushiShimizu, Tsukasa
Real Driving Emission (RDE) testing for motorcycles presents unique challenges due to the motorcycle’s lightweight construction, limited mounting space, and sensitivity to added mass and aerodynamic drag. Full-functional automotive Portable Emission Measurement Systems (PEMS), while highly accurate, are often impractical for two-wheelers as their weight and size can alter driving resistances, fuel consumption, and emission profiles, but also complicate installation and probably effect the drivability of the vehicle. To address these limitations, lightweight alternatives such as Mini-PEMS and ultralightweight alternatives such as Sensor-based Emission Measurement Systems (SEMS) offer compact, low-power solutions tailored for small vehicles. SEMS are typically equipped with lower cost sensors and low-tech gas conditioning systems compared to PEMS. Due to this these systems may not meet regulatory homologation requirements. Nevertheless, they provide justifiable accuracy for many real
Schurl, SebastianLienerth, PeterJaps, LeonidSchroeder, MatthiasSchmidt, StephanKirchberger, Roland
This paper provides insight into the theory and the applications of the order dispersion by crankpin arrangement, especially focusing on the enhancements of the structural reliability of the crankshaft and the sound quality of the outboard motor. In previous research, we developed the crankshaft which can balance by itself for V8 outboard motor with V bank angle of 60 degrees. We specifically showed the theoretical basis of the balancing and the measurement results of actual vibration levels on boat. Meanwhile, note that the crankshaft has a distinctive structure of crankpin offset angle of 60 degrees, so that combustion interval becomes unequal. As to the combustion, however, we just mentioned the effects on the engine output, not the practicality. In this paper, we firstly clarify the following dual benefits of the combustion in terms of the structural reliability and the sound quality. One is that the order dispersion resulting from unequal interval combustion can reduce the
Takanishi, KentaroMuramatsu, HidetaKondo, TakashiNaoe, Gaku
This study investigates the dynamic characteristics of the steering handlebar, termed "lean-over characteristics," by combining unmanned bicycle experiments with frequency response analysis. The focus is on the frequency response function from external lateral force to roll angle and steering angle, with particular attention to the relationship between these outputs. Subjective evaluations conducted by test riders revealed noticeable differences in steering feel between the two bicycle configurations. These differences were quantitatively explained by the gain and phase characteristics of the FRF between roll angular angle and steering angle, especially at approximately 7 Hz. The origin of this dynamic behavior was identified as zeros in the transfer function of roll angle. At this frequency, the external moment input and the inertial response of the vehicle body cancel each other out, resulting in suppressed roll motion and an enhanced steering response. Numerical simulations
Sakai, HidekiNakagawa, YoshihiroTezuka, YoshitakaYamashita, HirokiMiyagishi, Shunichi
This study delves into the dynamics of three-wheeled Personal Mobility Vehicles (PMVs) equipped with an active tilting mechanism. In three-wheeled vehicles with a single front wheel, the risk of tipping over during sudden braking and sharp turning is often highlighted. To address this issue, the authors have focused their research on three-wheeled PMVs with two front wheels and one rear wheel, equipped with an active tilting mechanism. Previous studies using dynamic simulation tools have demonstrated that such PMVs possess higher obstacle avoidance capabilities compared to motorcycles and even passenger cars. However, these simulations were based on the assumption of avoidance maneuvers without braking, and no studies have yet examined the behavior of three-wheeled PMVs with an active tilting mechanism under the more complex conditions of braking during turning. Therefore, prior to conducting dynamic simulations under braking and turning conditions, this study aims to clarify the
Haraguchi, TetsunoriKaneko, Tetsuya
Direct current (DC) systems are increasingly used in small power system applications ranging from combined heat and power plants aided with photovoltaic (PV) installations to powertrains of small electric vehicles. A critical safety issue in these systems is the occurrence of series arc faults, which can lead to fires due to high temperatures. This paper presents a model-based method for detecting such faults in medium- and high-voltage DC circuits. Unlike traditional approaches that rely on high-frequency signal analysis, the proposed method uses a physical circuit model and a high-gain observer to estimate deviations from nominal operation. The detection criterion is based on the variance of a disturbance estimate, allowing fast and reliable fault identification. Experimental validation is conducted using a PV system with an arc generator to simulate faults. The results demonstrate the effectiveness of the method in distinguishing fault events from normal operating variations. The
Winkler, AlexanderMayr, StefanGrabmair, Gernot
To mitigate greenhouse emissions such as carbon monoxide (CO), carbon dioxides (CO2), oxide of nitrogen (NOx) and particulate matter reduction Government of India implemented Bharat Stage VI (BS-VI) norms from year 2020. Moving to more stringent emission norms poses challenges for automakers in several ways such as meeting exhaust emissions, on board diagnostic, drivers’ inducement, and particulate filter monitoring on vehicle. It is imperative to upgrade engine management system for on-board diagnostics (OBD) that refers to a vehicles self-diagnostic and reporting ability. On board diagnostics systems enables owner of vehicle to gain access of the various vehicle sub-systems. OBD-II standards were made more rigid, requiring the malfunction indicator lamp (MIL) to be activated if emission-related components fail. Also, vehicle emissions carbon monoxide (CO), oxide of nitrogen (NOx) and particulate matter not to exceed OBD thresholds. Consequently, the use of specific oxide of nitrogen
Jagtap, PranjalSyed, KaleemuddinChaudhari, SandipKhairnar, GirishBhoite, VikramReddy, Kameswar
While hybrid electric powertrains are the standard for passenger cars, the application to motorcycles is almost nil. The reason is the increase in weight, cost and overall dimensions, which can compromise the layout and dynamics of the motorcycle. A viable path is to replace the standard internal combustion engine with a much smaller and lighter unit, which leaves room for the installation of the electric components. The 2-Stroke (2S) cycle technology, thanks to double cycle frequency and inherent simplicity, can be the key to reduce engine dimensions, weight and cost, while keeping high power outputs. The HybridTec project, discussed in this paper, aims to develop a compact and lightweight V-90° two-cylinder 2S engine, coupled to an electric motor installed downstream of the gearbox (P3 configuration). The total installed power should be about 110 kW. The engine features loop-scavenging, actuated by a crankshaft-driven supercharger, while an exhaust rotary valve and electronic fuel
Rinaldini, Carlo AlbertoScrignoli, FrancescoVolza, AntonelloMattarelli, EnricoMontanari, LucaMagnani, Gianluca
This study focuses on the technology for establishing design criteria for the piston pin circlip (hereinafter referred to as "circlip"), which is a component that holds the engine piston pin. During the development of high-revving engines, failure of the piston sometimes becomes a problem, and the main factors are fatigue failure of the piston and falling of the piston pin. The falling of the piston pin is caused by the circlip disengaging from the groove by the inertial force due to the vertical motion of the piston. The circlip is compressed to the size of the piston circlip groove and assembled to the piston. Therefore, in order to prevent the circlip from falling out, it is necessary to compress it more and increase the reaction force acting on the groove. However, this measure raises concerns about the deterioration of the ease of assembly of the circlip. Therefore, it is necessary to establish evaluation criteria that prevent the circlip from disengaging and deterioration of its
Ishizuka, AtsushiWatanabe, Naoto
In recent years, stricter emission regulations for internal combustion engines have been implemented, including controls on evaporative fuel vapors from motorcycle fuel systems. To comply with these regulations, motorcycles are increasingly adopting evaporative emission control (EVAP) systems equipped with carbon canisters. The carbon canister adsorbs fuel vapors while the vehicle is stationary, preventing them from being released into the atmosphere. During engine operation, the stored vapors are purged back into the engine by the vacuum in the intake manifold, thereby regenerating the canister. EVAP system development must ensure compliance with emission standards while minimizing any negative impact on engine performance. As regulations are expected to become stricter in the future, there is increasing demand for high-performing canisters and more effective purge systems. This highlights the need for more efficient development methods. The aim of this study is to enhance the
Okuno, KeisukeHidai, AtsuyaTorigoshi, MasakiKinoshita, Hisatoshi
Although exhaust gas regulations for internal combustion engines have been in place for quite some time, they are still getting stricter every year. Motorcycles are no exception. Exhaust gas regulations for after-degradation durability have already been applied, and the next regulation is expected to require vehicles in use in the market to meet the exhaust gas regulation values. Technology to comply with exhaust gas regulations mainly deals with catalyst performance degradation. The main issues are metal sintering and poisoning. In particular, it is difficult to explain clearly the change in catalyst performance due to poisoning alone, as it is necessary to distinguish it from sintering and to determine the distribution of deterioration. However, phosphorus poisoning from oil cannot be ignored unless oil consumption is reduced to zero. In order to understand the change in practical catalyst performance due to poisoning with a distribution of degradation, it is necessary to explain the
Ibara, TakeruItou, ShioriYusa, KazumaKinoshita, HisatoshiMotegi, Takuya
Yamaha Motor Engineering Co., Ltd. provides plastic processing technology based on fuel tank press forming technology, and is developing various plastic processing methods, including forging, and developing mold equipment to realize them. This time, the core parts of the YECVT unit mounted on Yamaha Motor Co., Ltd.'s small premium scooter "NMAX" were not made by welding individual parts to each other, but by integrally forming them from a single thick plate using the cold forming method, resulting in lightweight, compact, high-strength, high-precision parts. By incorporating a composite plastic processing method that takes advantage of the characteristics of the material while making full use of analysis technology and mold technology, we were able to develop a composite plastic processing method (plate forging method) that creates new added value and mass produce it. In addition,this development has made it possible to achieve a thickness increase of 1.7 times the standard material
Hongo, HironariTamaru, ShogoUda, Shinnosuke
This specification covers a corrosion-resistant steel in the form of investment castings homogenized, solution, and precipitation heat treated to 150 ksi (1034 MPa) minimum tensile strength.
AMS F Corrosion and Heat Resistant Alloys Committee
This numerical study investigates a spark-ignited, two-stroke engine employing uniflow scavenging, flathead cylinder head design, and an exhaust valve system to identify the optimal bore-to-stroke (B/S) ratio for maximizing brake efficiency at fixed displacement. A single-cylinder prototype engine was constructed, and its experimental data validated a 1D GT-SUITE simulation model. This validated model was then utilized to simulate a full-scale, 1.5-liter displacement, horizontally opposed four-cylinder engine with supercharger-assisted boosting, intended for small aircraft propulsion. The simulations explored a range of B/S ratios from undersquare (0.7) to oversquare (1.5), maintaining a consistent brake power output of 60 kW at 3000 rpm and lambda 0.9. Results showed that increasing the B/S ratio enhanced brake efficiency from 26.0% at B/S=0.7 to 27.0% at B/S=1.5, largely due to reduced frictional losses attributed to shorter stroke and lower piston speeds, decreased heat transfer
Zanchin, GuilhermeHausen, RobertoFagundez, Jean LuccaLanzanova, ThompsonMartins, Mario
There is growing demand for energy utilization due to stricter environmental emission norms to reduce greenhouse gases and other threats posed due to the emissions are major motivation factors for researchers to adopt on strategic plans to decrease the usage of energy and reduce the carbon contents of fuels, the usage of hydrogen or blend of hydrogen with CNG as a fuel in internal combustion engines is the best option. As hydrogen has lower volumetric energy density and higher combustion temperature, pure hydrogen-fueled engines produce lower power output and much higher NOx emissions than gasoline-fueled engine at stoichiometric air-fuel ratio. Blending of hydrogen with CNG provides a blended gas termed as hydrogen-enriched natural gas (hCNG). hCNG stands for hydrogen enriched compressed natural gas and it combines the advantages of both hydrogen and methane. The addition of Hydrogen to CNG has potential to even lower the CNG emissions and is the first step towards promotion of a
Syed, KaleemuddinChaudhari, SandipKhairnar, GirishSajjan lng, Suresh
The present study examines the influence of process parameters on the effect of strength and crystalline properties of AlSi10Mg alloy with laser sintered process. A detailed work was carried out with the effects of varying the laser power, scan speed, and hatch distance on crystalline structure, hardness, and surface roughness. From the analysis, the improved surface quality and mechanical performance were achieved with a scan speed of 1200 mm/s, a laser power of 370 W, and a hatch distance of 0.1 mm. An increase in hardness, improved surface finish, and reduced porosity was observed with decreased hatch distance. However, the balanced results were obtained for scanning speed of 1200 mm/s and laser power of 370 W. The ideal processing conditions decreased the crystalline size, increasing the overall material strength, when crystalline analysis was carried out. The higher scanning speeds supported improved grain refinement and heat diffusion, with the poor hardness value. With the lower
Shailesh Rao, A.
Stringent European carbon dioxide (CO2) emission regulations have stimulated the development of alternative technologies such as Dual Fuel (DF), which involves partially replacing fossil fuel with a low-carbon alternative. Hydrogen represents an ideal candidate for DF due to its properties, including the absence of carbon, high flame propagation speed, and high diffusivity. This study analyzes the combustion and performance of a 1.0L, naturally aspirated, three-cylinder in-line compression ignition off-road engine with a 17.5:1 compression ratio, originally equipped with a conventional diesel system and modified for diesel-hydrogen dual fuel operation. Three Port Fuel Injectors (PFI) are installed in the intake manifold for hydrogen injection. Additionally, they are strategically positioned to minimize the volume between the intake valve and injector tip. Tests were conducted at a fixed engine speed of 2000 rpm, varying the engine load from 30% to 85% of maximum torque. The diesel
Rossetti, SalvatoreMancaruso, Ezio
The use of alternative fuels, such as biofuels and synthetic fuels in small mobility engines has become more common these days. Although these fuels contribute to the carbon neutrality, it is known that they do not have a certain fuel composition, which significantly affects the combustion characteristics of an engine, such as knocking and combustion duration. Therefore, to get the most out of these sustainable fuels, it is necessary to develop engine systems that are highly robust to variations in fuel composition. To achieve this goal, a method to sense fuel characteristics onboard using sensors already widespread in use or can be installed inexpensively is required. Although in-cylinder piezoelectric pressure sensors are useful for research in the laboratory, it is not suitable for the use in commercial engines because of its high cost. Therefore, the use of other sensors should be considered. The purpose of this study is to experimentally analyze what information related to
Hayashi, KoheiKim, JihoonYamasaki, Yudai
In recent years, diesel engine emissions regulations have been strengthened worldwide, necessitating the evaluation of regulatory values under transient conditions. Consequently, the need to assess transient states in the development of diesel engines has increased significantly. The evaluation using MBD (Model Based Development) is considered a promising method for achieving both low fuel consumption and simultaneous reduction of NOx and soot emissions. However, the mechanism of soot formation is complex, making it challenging to model mathematically directly. In this paper, hybrid machine learning approaches combining a physical model and a machine learning model are used to validate the prediction of soot emissions under transient conditions in a diesel engine with an EGR system. Various parameters such as fuel consumption and emissions predicted by the physical model are compared with measurements to validate the accuracy of the physical model. The prediction of soot emissions by
Kitamura, TakahiroMatsuoka, AyanoSuematsu, KosukeOkano, Hiroaki
In order to improve engine emission and limit combustion instabilities, in particular for low load and idle conditions, reducing the injected fuel mass shot-to-shot dispersion is mandatory. Unfortunately, the most diffused approach for the hydraulic analysis of low-pressure injectors such as PFIs or SCR dozers is restrained to the mean injected mass measurement in given operating conditions, since the use of conventional injection analyzers is unfeasible. In the present paper, an innovative injection analyzer is used to measure both the injection rate and the injected mass of each single injection event, enabling a proper dispersion investigation of the analysed low pressure injection system. The proposed instrument is an inverse application of the Zeuch’s method, which in this case is applied to a closed volume upstream the injector, with the injector being operated with the prescribed upstream-to-downstream pressure differential. Further, the injector can inject freely against air
Postrioti, LucioMaka, CristianMartino, Manuel
This paper describes the design and characteristics of the knock sensor. The sensor is already used as a commodity product for automotive applications and used by all automotive OEMs for spark ignited combustion engines. With the arrival of the electronic fuel injection on the two wheelers, further optimization of the combustion can be obtained. Although there are many publications on the engine knock strategy, little is known publicly about the sensor itself. The knock sensor is an accelerometer based on a piezoelectric component; it provides an analog signal of the engine vibration. The Electronic Control Unit will filter the signal according to a specific strategy and defines the presence and intensity of the engine knock. The ECU will act accordingly on the ignition timing. The inner structure as well as the mechanical and electrical interface are described in this article.
van Est, JeroenPrieu, Corentin
The water pump is the crucial component of the engine cooling system. It is usually designed considering as rated conditions the ones evaluated when the engine delivers its maximum power. This results in an overdesign of the pump, considering that almost never the engine delivers the maximum power, in usual operation. At these conditions, in fact, flow rate and pressure delivered reach the maximum values, which are not needed to cool the engine in most probable operating conditions. In fact, considering the real operating conditions during a typical driving mission or a homologation cycle, the mechanical power is far away from the maximum datum, as well as the cooling flow rate and pressure delivered by the pump. To a so unbalanced design for the pump corresponds a low efficiency of it, being the technology oriented to use a centrifugal type, whose efficiency is quite dependent on speed of revolution and flow rate delivered. Hence, modifying the design point of the pump causes a
Di Battista, DavideDeriszadeh, AliDi Prospero, FedericoDi Giovine, GiammarcoDi Bartolomeo, MarcoFatigati, FabioCipollone, Roberto
Recent climate changes, driven by greenhouse gas emissions, along with global regulations aimed at mitigating these effects, have intensified research on carbon-free fuels. Among these, hydrogen stands out as one of the most promising options. In this study, use is made of a recent 1D kernel expansion model developed by the authors, which is based on the conservation equations of mass, energy and deficient reactant. The theory of transient thermo-diffusion is also adopted to estimate the reactant and temperature gradients at the outer flame surface. The kernel expansion model accounts for the variability of thermodynamic properties both inside and outside the flame volume, including high-temperature ionization and dissociation effects. The kernel expansion model is used until the non-linear stretch effects are sufficiently relaxed. Subsequently, the propagation of the premixed flame is described by means of a two-zone combustion model. During both phases, the effects of hydrodynamic
Pretto, MarcoBozza, FabioGiannattasio, PietroDe Bellis, VincenzoUgliano, Emanuele
Evaluating the impact of software changes on fuel consumption and emissions is a critical aspect of transmission development. To evaluate the trade-offs between performance improvements and potential negative effects on efficiency, a forward-looking Software-in-the-Loop (SiL) simulation has been developed. Unlike backward calculations that derive fuel consumption based solely on cycle speed and engine speed, this approach executes complete driving cycles as the Worldwide Harmonized Light-Duty Vehicle Test Cycle (WLTC) within a detailed SiL environment. By considering all relevant influencing factors in a dynamic simulation, the method provides a more accurate assessment of fuel consumption and emission differences between two versions of the transmission software. The significant contribution of this work lies in the high-fidelity integration of a real virtual Transmission Control Unit (vTCU) software within a comprehensive, validated forward-looking SiL environment. This approach
Kengne Dzegou, Thierry JuniorSchober, FlorianRebesberger, RonHenze, Roman
This study investigates emissions from motorcycles, focusing on both regulated gaseous pollutants (e.g., CO, NOx, HC) and particulate number (PN) emissions, which are non-regulated for this vehicle category in the actual EU emission regulation. Using a state-of-the-art testbench setup equipped with advanced exhaust gas analysis and particle measurement programme (PMP) system, emissions were analyzed under both standardized homologation cycles (WMTC) and more dynamic Real Driving Cycles (RDCs). Besides the measurement results the technological differences between different motorcycle categories are described. This is followed by a discussion of the influences of engine and exhaust gas aftertreatment systems on emission. The findings reveal, that there are two different subcategories of two-wheeler, which show different emission characteristics. L1e vehicles showed increased emissions compared to passenger cars, caused by the absence of advanced exhaust aftertreatment and on-board
Schurl, SebastianSchmidt, StephanBretterklieber, NikoKupper, MartinKirchberger, Roland