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Ride Quality and Drivability of a Typical Passenger Car subject to Engine/Driveline and Road Non-uniformities ExcitationsNickmehr, Neda January 2011 (has links)
The aim of this work is to evaluate ride quality of a typical passenger car. This requires both identifying the excitation resources, which result to undesired noise inside the vehicle, and studying human reaction t applied vibration. Driveline linear torsional vibration will be modelled by a 14-degress of freedom system while engine cylinder pressure torques are considered as an input force for the structure. The results show good agreement with the corresponding reference output responses which proves the accuracy of the numerical approach fourth order Runge-kutta. An eighteen-degree of freedom model is then used to investigate coupled motion of driveline and the tire/suspension assembly in order to attain vehicle body longitudinal acceleration subject to engine excitations. Road surface irregularities is simulated as a stationary random process and further vertical acceleration of the vehicle body will be obtained by considering the well-known quarter-car model including suspension/tire mechanisms and road input force. Finally, ISO diagrams are utilized to compare RMS vertical and lateral accelerations of the car body with the fatigue-decreased proficiency boundaries and to determine harmful frequency regions. According to the results, passive suspension system is not functional enough since its behaviour depends on frequency content of the input and it provides good isolation only when the car is subjected to a high frequency excitation. Although longitudinal RMS acceleration of the vehicle body due to engine force is not too significant, driveline torsional vibration itself has to be studied in order to avoid any dangerous damages for each component by recognizing resonance frequencies of the system. The report will come to an end by explaining different issues which are not investigated in this thesis and may be considered as future works.
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Modeling and Control of a Parallel HEV Powertrain with Focus on the ClutchMorsali, Mahdi January 2015 (has links)
Nowadays, the increasing amount of greenhouse gases and diminishing of the existing petroleum minerals for future generations, has led the automotive companies to think of producing vehicles with less emissions and fuel consumption. For this purpose, Hybrid Electric Vehicles (HEVs) have emerged in the recent decades. HEVs with different configurations have been introduced by engineers.The simulation platform aim for a parallel HEV, where the intention is to reduce the emissions and fuel consumption. The simulation platform includes an Electric Motor (EM) in addition to an Internal Combustion Engine (ICE). A new transmission system is modeled which is compatible with parallel configuration for the HEV, where the inertial effects of the gearbox, clutch and driveline is formulated. The transmission system includes a gearbox which is equipped with synchronizers for smooth change of gears. The HEV is controlled by a rule based controller together with an optimization algorithm as power management strategy in order to have optimal fuel consumption. Using the rule based controller, the HEV is planned to be launched by EM in order to have a downsized clutch and ICE. The clutch modeling is the main focus of this study, where the slipping mechanism is considered in the simulation. In the driveline model, the flexibility effects of the propeller shaft and drive shaft is simulated, so that the model can capture the torsional vibrations of the driveline. The objective of modeling such a system is to reduce emissions and fuel consumption with the same performance of the conventional vehicle. To achieve this goal first a conventional vehicle is modeled and subsequently, a hybrid vehicle is modeled and finally the characteristics of the two simulated models are studied and compared with each other. Using the simulation platform, the state of charge (SOC) of the battery, oscillations of propeller shaft and drive shaft, clutch actuations and couplings, energy dissipated by the clutch, torques provided by EM and ICE, fuel consumptions, emissions and calculation time are calculated and investigated. The hybridization results in a reduction in fuel consumption and emissions, moreover, the energy dissipated by the clutch and clutch couplings are decreased.
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Design of a High Altitude Wind Power Generation SystemAziz, Imran January 2013 (has links)
One of the key points to reduce the world dependence on fossil fuels and the emissions of greenhouse gases is the use of renewable energy sources. Recent studies showed that wind energy is a significant source of renewable energy which is capable to meet the global energy demands. However, such energy cannot be harvested by today’s technology, based on wind towers, which has nearly reached its economical and technological limits. The major part of the atmospheric wind is inaccessible to the conventional wind turbines and wind at higher altitude is the major source of potential energy which has not been fully exploited yet. The thesis paper has presented a study aimed to devise a new class of wind generator based on extracting energy from high altitude wind.A brief theoretical study is presented to evaluate the potential of an innovative high altitude wind power technology which exploits a tethered airfoil to extract energy from wind at higher altitude. Among the various concepts proposed over last few decades, a kite power system with a single kite is selected for the design purpose.The designed ground station is an improvisation over existing prototypes with an energy reservoir for having a continuous power output. A flywheel is used as the energy storage system which stores the extra energy during traction phases and supplies it during recovery phases and thus giving a continuous power generation regardless of the kite’s motion and keeping the rotor speed in a permissible range defined by the design constraints. Manufacturability of the structure, availability of the components, safety and maintenance criteria have been taken into account while building the ground station CAD model.A dynamic simulation model is developed to investigate the power transmission system of the kite power unit which reflects the torque, speed and power behaviour of the modelled ground station driveline. The functionality of the designed model for the selected concept is tested with several numerical and graphical examples.
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Převodovka pro pohon přední nápravy vozidla / Car Front Axle Driveline GearboxČernuško, Lukáš January 2017 (has links)
Goal of the Master Thesis was to design conception of electric vehicle driveline, which is able of torque vectoring between each wheel independently and to design front axle gearbox. The aim was to use up the car on race track and to test dynamic properties of electric vehicle for follow-up development. Due to determined requirements and possible solutions the conception of driveline was designed and basic parameters were defined. The main part of the thesis contains a design of gearbox including strength calculation of gearing, the control of shafts to fatigue and elasticity limiting states, life of selected bearings. Gearbox case was subjected to FEM analysis. The last chapter uses simulation to gain vehicle acceleration. Designed electric driveline is applicable to other sport vehicles after some modifications.
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Návrh mechanické části pohonu zadní nápravy elektromobilu / Electric Car Rear Axle Mechanic Driveline DesignBaroš, Eduard January 2017 (has links)
The aim of the diploma thesis is the design of mechanical parts of the rear axle driveline suitable for rebuilding of a given sports car into an electric car. The introductory part briefly explains the physical principles of the drive and contains a brief summary of the current concepts of electric vehicle propulsion. Afterwards, there is a comparison and selection of a suitable concept for a given electric vehicle, determination of the basic vehicle parameters based on the calculation of the longitudinal vehicle dynamics and the gearbox calculation on the basis of which the design is solved. The next part is dedicated to the computational inspection of parts using the finite element method. The final part deals with the placement of the assembly inside the vehicle and the evaluation of the drive mechanism.
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Assessment of Nonlinear Damping Elements for Vibro-Impacts inAutomotive Torsional Systems with Discontinuous NonlinearitiesSaleh, Almahdi January 2015 (has links)
No description available.
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System Simulation of Electric Driveline and Active Suspension using Simcenter AmesimLundberg, Simon January 2022 (has links)
Computer simulation software’s are arguably some of the most convenient and utilized tools for an engineer as it lets them model real phenomena and observe different operations without having to perform the operation physically, thus saving both time and resources. Naturally these tools varies in design depending on their intended area of application and while a large number of them supports modeling of more than one physical domain, it is often cumbersome to attain a functional interaction between them. In spite of this there do exist simulation software that have been specifically developed for effectively integrating several physical domains known as system simulation software’s. One of these are Siemens Simcenter Amesim, a computer simulation software for modeling multi domain mechatronic systems. One company that has recently found an interest in potentially adapting the concept of system simulations into their workflow is BAE Systems Hägglunds, Örnsköldsvik, where a pre-study has previously been conducted in order to define a system requirement specification as well as narrow down the number of promising tools to only a few, with Simcenter Amesim being one of them. The aim of this study is then to evaluate and assess to what degree Simcenter Amesim complies with the requirements specified by the company. The primary source of information in which this analysis will be based upon is through the modeling of two different pilot cases in Simcenter Amesim, an electric driveline as well as the hydraulic component of the active suspension system affiliated with the CV90 vehicle. The electric driveline was developed as a general model featuring a few key functionalities in terms of power setup. This being that two electric motors were to be utilized, one for driving the vehicle forward and the other for steering the vehicle left and right. Powering these two was then an electric generator which by itself was to be powered by an internal combustion engine (ICE). The active suspension system was modeled based on existing schematics and information available through company resources with the ambition of realizing a certain behavior of the system as described by a couple of real tests made. Results from simulations made using the electric driveline model indicates that the model succeeds in fulfilling its fundamental functionality. Through plain throttle and steering inputs the corresponding vehicle is able to move about in a simple and predictable fashion with data also showcasing realistic behavior in terms of velocity evolution and power generation. The hydraulic model of the CV90 active suspension system furthermore appears to replicate the behavior of the actual suspension system fairly well based on the real test data available. Analogous with both models however is the fact that they are rather primitive in their current state. The electric driveline model lacks some of the finesses and functionalities that are included in modern driveline systems, mostly coupled to the component steering and feedback system which is more arbitrarily implemented in this model. As for the hydraulic suspension system it would be beneficial to continue develop the model through further evaluation using more real life test data.
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Development of Friction/Blended Braking Capability for an Electric Driveline Model for Multi-Scale Road-Cargo Simulations / Utveckling av friktion/blandad Bromsförmåga för en elektrisk Drivlinjemodell för Multi-Scale Road-Cargo SimuleringarWu, Fangge January 2023 (has links)
This thesis focuses on the critical development of friction and blended braking capabilities for an electric driveline model intended for multiscale road-cargo simulations. In the rapidly evolving landscape of transportation, electric driveline technology has emerged as a key player in achieving sustainability and efficiency goals. This study addresses the pivotal aspect of braking performance within this context, aiming to optimize energy utilization and enhance road safety. Using a systems engineering approach, MATLAB, and Simulink, the work in this thesis focused on the construction of a comprehensive model of a Volvo FH truck with friction/blended braking and an Anti-lock Braking System (ABS). The model underwent rigorous validation against the New European Driving Cycle (NEDC) and subsequent simulation under NEDC, US06, WLTC3 driving cycles. The primary objective was to assess the impact of activating or deactivating the blended control system on the State of Charge (SOC) and energy consumption. Through iterative refinement, the model's energy consumption per kilometer closely approximated actual FH truck test values. Activating the blended control system consistently led to reduced energy consumption across all driving cycles, underscoring its potential to enhance sustainable and safe transportation solutions. Importantly, the ABS system functioned effectively throughout the simulations, ensuring vehicle safety, while the model maintained a consistent output speed aligned with the input speed. This abstract summarizes the research's focus, methodology, and key findings, highlighting the successful development and validation of a Volvo FH truck model with friction/blended braking and ABS systems. The results underscore the blended control system's capacity to improve energy efficiency, contributing to the pursuit of sustainable and efficient transportation solutions in the evolving landscape of electric driveline technology. / Detta examensarbete fokuserar på utvecklingen av en elektrisk drivlinemodell som inkluderar mixning av konventionell friktionsbromssystem och den elektriska drivlinans moment under regenerering. Modellen är avsedd för multiskaliga väg-och godstransportsimuleringar. I den snabbt föränderliga transportsektorn är elektrisk drivlineteknologi en viktig del för att uppnå hållbarhets- och effektivitetsmål. Detta arbete behandlar den avgörande aspekten av bromsprestanda i detta sammanhang och har som mål att optimera energianvändningen och kontrollera vägsäkerheten. Genom att använda s.k. systems engineering-metodik, MATLAB och Simulink, utvecklades en dynamisk modell av en Volvo FH-lastbil med friktions-/mixad bromsning och system för låsningsfria bromsar (ABS). Modellen genomgick en rigorös validering mot New European Driving Cycle (NEDC) och efterföljande simuleringar enligt NEDC, US06 och WLTC3-körcykler. Det primära målet var att bedöma effekten av att aktivera eller inaktivera det mixade kontrollsystemet på laddningsnivå (SOC) och energiförbrukning. Genom iterativ förbättring approximerade modellen energiförbrukningen per kilometer nära de faktiska provvärdena för FH-lastbilar. Aktivering av det blandade kontrollsystemet ledde konsekvent till minskad energiförbrukning för alla körcykler och underströk dess potential att förbättra hållbara och säkra transportsystem. Det är viktigt att notera att ABS-systemet fungerade effektivt genom alla simuleringar och säkerställde fordonssäkerheten, samtidigt som modellen beräknade en hastighet i linje med körcykelns specificerade hastigheten. Denna sammanfattning sammanfattar forskningens fokus, metodik och huvudsakliga resultat och lyfter fram den framgångsrika utvecklingen och valideringen av en Volvo FH-lastbilsmodell med friktions-/mixad bromsning och ABS-system. Resultaten understryker det blandade kontrollsystemets förmåga att förbättra energieffektiviteten och bidra till strävan efter hållbara och effektiva transportsystem i den snabbt föränderliga världen av elektrisk drivlineteknologi.
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Robust Torque Control for Automated Gear Shifting in Heavy Duty Vehicles / Robust Momentreglering vid Automatiserad Växling i Tunga FordonAbrahamsson, Henrik, Carlson, Peter January 2008 (has links)
<p>In an automated manual transmission it is desired to have zero torque in the transmission when disengaging a gear. This minimizes the oscillations in the driveline which increases the comfort and makes the speed synchronization easier. The automated manual transmission system in a Scania truck, called Opticruise, uses engine torque control to achieve zero torque in the transmission.In this thesis different control strategies for engine torque control are proposed in order to minimize the oscillations in the driveline and increase the comfort during a gear shift. A model of the driveline is developed in order to evaluate the control strategies. The main focus was to develop controllers that are easy to implement and that are robust enough to be used in different driveline configurations. This means that model dependent control strategies are not considered.A control strategy with a combination of a feedback from the speed difference between the output shaft speed and the wheel speed, and a feedforward with a linear ramp, showed very good performance in both simulations and tests in trucks. The amplitude of the oscillations in the output shaft speed after neutralengagement are halved compared to the results from the existing method in Scania trucks. The new concept is also more robust against initial conditions and time delay estimations.</p>
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Robust Torque Control for Automated Gear Shifting in Heavy Duty Vehicles / Robust Momentreglering vid Automatiserad Växling i Tunga FordonAbrahamsson, Henrik, Carlson, Peter January 2008 (has links)
In an automated manual transmission it is desired to have zero torque in the transmission when disengaging a gear. This minimizes the oscillations in the driveline which increases the comfort and makes the speed synchronization easier. The automated manual transmission system in a Scania truck, called Opticruise, uses engine torque control to achieve zero torque in the transmission.In this thesis different control strategies for engine torque control are proposed in order to minimize the oscillations in the driveline and increase the comfort during a gear shift. A model of the driveline is developed in order to evaluate the control strategies. The main focus was to develop controllers that are easy to implement and that are robust enough to be used in different driveline configurations. This means that model dependent control strategies are not considered.A control strategy with a combination of a feedback from the speed difference between the output shaft speed and the wheel speed, and a feedforward with a linear ramp, showed very good performance in both simulations and tests in trucks. The amplitude of the oscillations in the output shaft speed after neutralengagement are halved compared to the results from the existing method in Scania trucks. The new concept is also more robust against initial conditions and time delay estimations.
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