Powertrain

Dynamic behaviour of automotive dry clutches depends on the frictional characteristics of the contact between the friction lining material, the flywheel and the pressure plate during the clutch engagement process. During engagement due to high interfacial slip and relatively high contact pressures, generated friction gives rise to contact heat, which affects the material behaviour and the associated frictional characteristics. In practice excess interfacial slipping and generated heat during torque transmission can result in wear of the lining, thermal distortion of the friction disc and reduced useful life of the clutch.
This paper provides measurement of friction lining characteristics for dry clutches for new and worn state under representative operating conditions pertaining to interfacial slipping during clutch engagement, applied contact pressures and generated temperatures. An analytical thermal partitioning network model of the clutch assembly, incorporating the flywheel, friction lining and the pressure plate is presented, based upon the principle of conservation of energy. The results of the analysis show a higher coefficient of friction for the new lining material which reduces the extent of interfacial slipping during clutch engagement, thus reducing the frictional power loss and generated interfacial heating. The
generated heat is removed less efficiently from worn lining. This might be affected by different factors observed such as the reduced lining thickness and the reduction of density of the material but mainly due to poorer thermal conductivity due to the depletion of copper particles in its microstructure as the result of wear.
The study integrates frictional characteristics, microstructural composition, mechanisms of heat generation, effect of lining wear and heat transfer in a fundamental manner, an approach not hitherto reported in literature.

There is a grave problem of air pollution in India. In 2019, 21 of the 30 most polluted cities in the world were from
India. A study done in 2016 shows that at least 14 million people in India breathe air that is ten times over the WHO safe limit.
27% of pollution is spread by vehicles. There are more than when it comes to e-mobility, it is not just about electric vehicles.
Hybrid vehicles are being seen as a temporary way to fill the gap between conventional vehicles and EVs. since EV charging
infrastructure is still not created in India where, hybrid vehicles can make a difference in the short to medium term. There is dire
need to adopt HEVs in order to prevent an immense increase in climate change and limited natural resources on our planet.
This paper is focused on the review of the classification of the HEV powertrains based on hybrid vehicle configurations. The
advantages and disadvantages of serial, parallel, or power-split/series-parallel hybrids are also discussed.

A tribo-dynamics model, predicting the conjunctional inefficiency and dynamic response of automotive hypoid gear pairs is presented. A dynamics model is coupled with an analytical friction model (viscous and boundary). The temperature rise at the centre of the conjunction is accounted for through use of thermal network model and Time Temperature Superposition (TTS) method, as well as the time varying geometry of the meshing gear teeth. Newtonian and non-Newtonian lubricant shear behaviour are both considered Surface topography measurements of a run-in pinions are obtained. Inefficiency calculations are performed for typical automotive drive cycle snapshots. Precisely measured lubricant shear characterstics for lubricants different blended viscosity modifiers and evolving surface topography are used in the study of transmission inefficiency. The integrated thermal-tribodynamic analysis is shown to distinguish between different viscosity modifier types, an approach not hitherto reported in literature.

Downsizing of transmission boxes and economic pressures in manufacture has gradually led to changed sealing conditions in passenger cars. Radial shaft seals are widely used in power transmission systems to prevent oil leakage from the system. Leaking transmission systems can lead to both environmental pollution and excessive warranty costs. It is essential to develop a dedicated experimental rig to simulate the transmission system operation under controlled environment, providing access for various sensors and data acquisition systems. A pre-requisite for representative rig design is to determine the in situ vehicle conditions which must be replicated in such  a design. The paper reports on the evaluation of these in situ conditions, particularly the imposed vehicular vibration conditions.

In-wheel traction allows simplicity and freedom for the design of hybrid-electric/electric vehicle (HEV/EV). However, the in-wheel motor increases the unsprung mass and hence deteriorates ride comfort and reduces the road holding capability of the car. To solve these problems, this paper proposes an indirect drive in-wheel traction system including a lightweight in-wheel drive and a specially designed rear suspension. A prototype of the in-wheel drive is designed based on the vehicle model of Volkswa-gen (VW) Lupo 3L. The prototype analysis shows that the proposed in-wheel system gives a balanced distribution of the vehicle weight and thus improves ride comfort. Design principles of the electrical motor used for this in-wheel system is further investigated. By reducing the permanent magnet height, the field weakening capability of a 24-slot 8-pole surface permanent magnet synchronous motor is visibly improved.

The Hybrid Electric Vehicle (HEV) powertrain, and an efficient power conversion and energy transmission process, are significant factors to reduce conventional fuel consumption and vehicle gas emission. The scale of gas emission of an HEV depends on an efficient design process for the powertrain and an optimal energy management system. Therefore, this paper models an efficient powertrain and energy transmission process for both series and parallel HEVs, which can contribute to the emission reduction process. Different power conversion stages, energy transmission paths, emissions, and a systems response corresponding to the driver’s profile are analyzed systematically. Finally, the emission of the proposed system is compared with the European standard of vehicle gas emission .

When speaking of quantification of the efficiency of a system, we mean the calculation of its thermodynamic efficiency, defined as the mathematical ratio between the input energy, i.e. the energy entering the considered system (in any of its forms: electric, chemical, thermal …), and the output energy (once more, in any of its forms), expressed with a pure number (between 0 and 1) or as percentage. The quantification of the efficiency is not a simple operation because it implies a very precise control of the energy flows that cross the boundary of the analysed system, but it is always useful as it is associated to the goodness of the energy transformations that occur inside that system. How characterizing the efficiency of agricultural machines A

Spherical cam-follower mechanisms are attractive alternatives to bevel gears, as they provide low backlash and low friction losses. The design of such a mechanism is reported here, to be incorporated in an automotive differential, whose bevel pinions and side gears are substituted by spherical cams and roller-carriers, respectively. Critical to the design of cam mechanisms is the generation of the cam-profile, free of undercutting. The profile, generated using computer algebra, is analyzed for singularities, including cusps and double points. The pressure angle, an important factor that governs the effective force transmission of cam mechanisms, is duly kept within acceptable limits. Conclusions are drawn on the suitability of cam mechanism developed for automotive applications.

Automated collection of on-vehicle sensor data allows the development of artificial intelligence (AI) techniques for vehicular systems’ diagnostic and prognostic processes to better assess the state-of-health, predict faults and evaluate residual life of ground vehicle systems. One of the vital subsystems, in terms of safety and mission criticality, is the power train, (comprising the engine, transmission, and final drives), which provides the driving torque required for vehicle acceleration. In this paper, a novel health and usage monitoring system (HUMS) architecture is presented, together with dedicated diagnosis/prognosis algorithms that utilize data gathered from a sensor network embedded in an armoured personnel carrier (APC) vehicle. To model the drivetrain, a virtual dynamometer is introduced, which estimates the engine torque output for successive comparison with the measured torque values taken from the engine control unit. This virtual dynamometer is also used in conjunct...

Para atingir melhores resultados na Shell Eco-Marathon, é essencial que todas as equipes deem seu melhor em prol de diminuir as perdas energéticas existentes no protótipo bem como desenvolver métodos que utilizem da melhor maneira a energia proveniente do motor. Após meses de pesquisa da equipe de trem de força do Grupo Santa Cruz (UESC), surgiu a necessidade de conhecer o comportamento energético do motor utilizado pela equipe para, assim, definir o regime de trabalho em que o motor apresente a maior eficiência. Para isso, uma investigação foi executada para diversos pontos de operação do motor variando-se a razão ar - combustível e encontrando a alimentação ideal para cada combinação torque x velocidade angular. A aplicação de carga foi executada com o auxílio de um dinamômetro hidráulico e o controle da alimentação através de um sistema de injeção eletrônica de combustível. Foi possível conhecer as condições nas quais o motor apresenta sua maior autonomia de trabalho, bem como quantificar a sua eficiência. O ponto de maior eficiência encontrado para o motor em questão foi de 28,25% em 5000 RPM x 2 N.m.

Automated collection of on-vehicle sensor data allows the development of artificial intelligence (AI) techniques for vehicular systems' diagnostic and prognostic processes to better assess the state-of-health, predict faults and evaluate residual life of ground vehicle systems. One of the vital subsystems, in terms of safety and mission criticality, is the power train, (comprising the engine, transmission, and final drives), which provides the driving torque required for vehicle acceleration. In this paper, a novel health and usage monitoring system (HUMS) architecture is presented, together with dedicated diagnosis/prognosis algorithms that utilize data gathered from a sensor network embedded in an armoured personnel carrier (APC) vehicle. To model the drivetrain, a virtual dynamometer is introduced, which estimates the engine torque output for successive comparison with the measured torque values taken from the engine control unit. This virtual dynamometer is also used in conjunction with other sensed variables to determine the maximum torque output of the engine, which is considered to be the primary indicator of engine health. Regression analysis is performed to capture the effect of certain variables such as engine hours, oil temperature, and coolant temperature on the degradation of maximum engine torque. Degradations in the final drives system were identified using a comparison of the temperature trends between the left-hand and right-hand final drives. This research lays foundations for the development of real-time diagnosis and prognosis functions for an integrated vehicle health management (IVHM) system suitable for safety critical manned and unmanned vehicle applications.

A study on plug-in hybrid electric recreational boat (PHERB) powertrain with a special energy management strategy modeling and analysis was presented in this paper. Firstly, the boat components are sized to meet the expected power and energy requirements through a power flow analysis. Then, the model is tested numerically in the MATLAB/SIMULINK environment using the existing driving cycle. The accuracy of the model is verified by a comparison of the component between the simulation results from PHERB and advanced vehicle simulator (ADVISOR) software. The simulation results of component, fuel economy and emission of PHERB and hybrid electric vehicle models in ADVISOR are compared.

The transport sector is responsible for almost 60% of oil consumption in OECD (Organization for Economic Cooperation and Development) countries, it is a major source of pollution and greenhouse gas emissions and it is the chief sector driving future growth in ...

The development of hybrid vehicular power systems has been conducted for decades to improve transportation quality mainly in terms of environment pollution and fuel economy. Hence, hybrid electric vehicular systems are considered an attractive and potential solution in the long run to replace conventional combustion engine vehicles. In this paper, a scaled-down vehicular powertrain test bench is designed and constructed utilizing a hybrid fuel cell/battery energy sources. The performance of the proposed test bench is also investigated experimentally to explore the modes of operation for system components under various road conditions. Load-following energy management strategy is implemented experimentally in this hybrid configuration. The concepts that can be learned from such test bench are certainly essential for any future implementation on real full-size vehicles. In this study, it is shown that even though fuel cells have a good energy-to-weight ratio, they have a slow response...

This paper describes the use of Hardware-in-Loop (HIL) simulation and Rapid Control Prototyping (RCP) tools for the accelerated design and optimization of battery management systems (BMS) typically found in hybrid/electric vehicles. The BMS is an electronic system that manages a rechargeable battery pack. Its functions include monitoring the cell/pack voltage, current, temperature, state-of-charge, depth-of-discharge, and state-of-health. Besides reporting this data to a supervisory (powertrain) controller, the BMS protects the battery by preventing it from operating outside its safe operating range and balancing the individual cells. Programming, testing and validation of the BMS with real batteries is a time-consuming, expensive and potentially dangerous operation since physical batteries needs to be discharged and re-charged for every development iteration. With the help of virtual batteries models as part of a HIL simulation, the BMS algorithm can be developed, calibrated and validated in a very secure and time-efficient manner resulting in a significant product development time reduction.

The transport sector is responsible for almost 60% of oil consumption in OECD (Organization for Economic Cooperation and Development) countries, it is a major source of pollution and greenhouse gas emissions and it is the chief sector driving future growth in ...

Automated collection of on-vehicle sensor data allows the development of artificial intelligence (AI) techniques for vehicular systems’ diagnostic and prognostic processes to better assess the state-of-health, predict faults and evaluate residual life of ground vehicle systems. One of the vital subsystems, in terms of safety and mission criticality, is the power train, (comprising the engine, transmission, and final drives), which provides the driving torque required for vehicle acceleration. In this paper, a novel health and usage monitoring system (HUMS) architecture is presented, together with dedicated diagnosis/prognosis algorithms that utilize data gathered from a sensor network embedded in an armoured personnel carrier (APC) vehicle. To model the drivetrain, a virtual dynamometer is introduced, which estimates the engine torque output for successive comparison with the measured torque values taken from the engine control unit. This virtual dynamometer is also used in conjunct...

Para atingir melhores resultados na Shell Eco-Marathon, é essencial que todas as equipes deem seu melhor em prol de diminuir as perdas energéticas existentes no protótipo bem como desenvolver métodos que utilizem da melhor maneira a energia proveniente do motor. Após meses de pesquisa da equipe de trem de força do Grupo Santa Cruz (UESC), surgiu a necessidade de conhecer o comportamento energético do motor utilizado pela equipe para, assim, definir o regime de trabalho em que o motor apresente a maior eficiência. Para isso, uma investigação foi executada para diversos pontos de operação do motor variando-se a razão ar - combustível e encontrando a alimentação ideal para cada combinação torque x velocidade angular. A aplicação de carga foi executada com o auxílio de um dinamômetro hidráulico e o controle da alimentação através de um sistema de injeção eletrônica de combustível. Foi possível conhecer as condições nas quais o motor apresenta sua maior autonomia de trabalho, bem como quantificar a sua eficiência. O ponto de maior eficiência encontrado para o motor em questão foi de 28,25% em 5000 RPM x 2 N.m.