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Viewing 1 to 30 of 2967
2010-09-28
Journal Article
2010-32-0057
Junya Watanabe, Dai Arai, Masataka Tanaka, Takeru Abe, Atsushi Ogasawara, Masahiko Tsuchiya, Ryushi Tsubota
Large motorcycles have a strong recreational aspect. Therefore, in addition to the sportiness that comes from the direct torque feel and the comfort that comes from the ease of operations, users demand improvements to fuel economy from the perspective of the environment and riding economics. In order to satisfy these needs, we have developed the world's first dual clutch transmission (hereinafter referred to as DCT) for motorcycles. In order to make the DCT more compact, we adopted a dual shaft construction for the main shaft, two hydraulic clutches arranged in-line, the basic structure of the gear shift mechanism carried over from a manual transmission (hereinafter referred to as MT) vehicle, a hydraulic circuit consolidated into the engine side cover, and shared use of engine oil for clutch actuation. Through these innovations, it became possible to carry over the die of the crankcase used on the MT vehicle as well as being able to load it onto the same frame as the MT vehicle.
2010-04-12
Technical Paper
2010-01-0370
Maria Ivarsson, Jan Åslund, Lars Nielsen
For a fuel optimal gear shift control, when look ahead information is available, the impact of the automated manual transmission (AMT) gear-shifting process is analyzed. For a standard discrete heavy truck transmission, answers are found on when to shift gears, prior to or when in an uphill slope. The gear-shifting process of a standard AMT is modeled in order to capture the fuel and time aspects of the gear shift. A numerical optimization is performed by dynamic programming, minimizing fuel consumption and time by controlling fuel injection and gear. Since a standard AMT does not have look ahead information, it sometimes gears down unnecessarily and thus gives a significantly higher fuel consumption compared to the optimal control. However, if gearing down is inevitable, the AMT gear-shifting strategy, based on engine thresholds, is well-functioning so that the optimal control only gives marginal additional savings.
2010-04-12
Technical Paper
2010-01-0371
Heimo Hartlieb, Kyle Shawn Williams, Michael Hausmann
The majority of modern automatic transmissions make use of multiple Variable Force Solenoid (VFS) valves within the hydraulic controls. The requirements for the control of these valves are much more stringent in the latest transmission designs. This leads to challenging requirements for the electronic solenoid driver circuit used to regulate the current flowing through the solenoid valve coil. We have developed a current control method that is fundamentally different than those commonly used in solenoid driver circuits. This unique current control method results in several improvements in the key performance characteristics of the solenoid driver circuit, which in turn improves the performance of the transmission system. In addition, this new control method requires less effort to implement into a specific application than state of the art current control methods.
2010-04-12
Technical Paper
2010-01-0372
Baoyu Wu, Guo Xuexun, Jun Yan, Qi Sun
Speed ratio and clamping force are two of the metal-belt CVT control targets. Conventional control strategies can not correspond to the driver's intention or provide various driving environment. A fuzzy logic ratio control algorithm and a fuzzy logic clamping force control algorithm for a metal-belt CVT are proposed. Nevertheless, high-quality fuzzy control rule base and factors of FLC are difficult to gain because repeated tests and experts' experience are needed. Therefore, genetic algorithm (GA) is introduced to optimize the fuzzy control algorithms. Using the optimized fuzzy control algorithms, Metal-belt CVT control simulations were implemented. The results show that a faster response and better robustness can be gained when compared with those of the PID control.
2010-04-12
Technical Paper
2010-01-0409
John Jekl, Richard D. Berkmortel, Paula Armstrong
The main objective of this paper is to demonstrate how flow and solidification simulation were used in the development of a new gating system design for three different magnesium alloys; and to determine the relative castability of each alloy based on casting trials. Prototype tooling for an existing 3-slide rear wheel drive automatic transmission case designed for aluminum A380 was provided by General Motors. Flow and solidification simulation were performed using Magmasoft on the existing runner system design using A380 (baseline), AE44, MRI153M and MRI230D. Based on the filling results, new designs were developed at Meridian for the magnesium alloys. Subsequent modeling was performed to verify the new design and the changes were incorporated into the prototype tool. Casting trials were conducted with the three magnesium alloys and the relative castability was evaluated.
2010-04-12
Technical Paper
2010-01-0497
Vivek Yadav, Abhijit Vishnu Londhe, Santosh Mahadeorao Khandait
Reducing the vibrations in the powertrain is one of the prime necessities in today's automobiles from NVH and strength perspectives. The necessity of 4×4 powertrain is increasing for better control on normal road and off-road vehicles. This leads to bulky powertrains. The vehicle speeds are increasing, that requires engines to run at higher speeds. Also to save on material costs and improve on fuel economy there is a need for optimizing the mass of the engine/vehicle. The reduced stiffness and higher speeds lead to increased noise and vibrations. One more challenge a powertrain design engineer has to face during design of its transmission housings is the bending / torsional mode vibrations of powertrain assembly. This aggravates other concerns such as shift lever vibrations, shift lever rattle, rise in in-cab noise, generation of boom noise at certain speeds, etc. Hence, reducing vibrations becomes an important and difficult aspect in design of an automobile.
2011-04-12
Technical Paper
2011-01-0394
Zhe Xie
A system level analysis was carried out on the effect of flow forces on a flow control variable force solenoid (VFS) used in automatic transmissions. Classic flow force model was reviewed as a function of the pressure difference and the solenoid current. A force balance analysis was conducted on the spool valve in the VFS, in order to study the relationship among the control current, flow forces, spring forces, and flow area. Flow bench testing was used to characterize a specific flow control VFS by both the pressure drop and solenoid current, in forward and reverse flow directions. The behavior of flow control VFS valve is significantly affected by flow forces. A sub-system level model was thus created to predict the steady-state and dynamic behavior of the flow VFS valve, which can be used in a transmission system level analysis. The modeling results were compared against experimental data to show the validity of the methodology.
2011-04-12
Technical Paper
2011-01-0393
John Marano, Steven Moorman, John Czoykowski, Chinar Ghike
The achievable shift quality of a modern automatic transmission may be greatly affected by the equivalent rotational inertia of the gearbox and driveline components. New, more mass- and packaging-efficient higher number of gear powerflows are being developed. These new architectures often result in more components being attached to a given rotational node. The rotational speed multiplication of the components must be considered when determining their inertial torque contribution to a given speed change event. An example of this multiplication effect is presented, with a discussion of the resulting impact to shift quality disturbance. Opportunities to address the negative aspects of the higher inertial torque contribution to transmission output shaft disturbance are discussed. Coordination of engine torque control and clutch torque control is presented as a viable strategy to improve shift quality.
2011-04-12
Technical Paper
2011-01-0396
Kumaraswamy Hebbale, Chunhao Lee, Farzad Samie, Chi-Kuan Kao, Xu Chen, Jeremy Horgan, Scott Hearld
To realize better fuel economy benefits from transmissions, car makers have started the application of torque converter clutch control in second gear and beyond, resulting in greater demand on the torque converter clutch (TCC) and its control system. This paper focuses on one aspect of the control of the torque converter clutch to improve fuel economy and faster response of the transmission. A TCC is implemented to control the slip between the pump and turbine of the torque converter, thereby increasing its energy transfer efficiency and increasing vehicle fuel economy. However, due to the non-linear nature of the torque converter fluid coupling, the slip feedback control has to be very active to handle different driver inputs and road-load conditions, such as different desired slip levels, changes in engine input torques, etc. This non-linearity requires intense calibration efforts to precisely control the clutch slip in all the scenarios.
2011-04-12
Journal Article
2011-01-0395
Damien Le Guen, Thomas Weck, Adrien Balihe, Benoit Verbeke
Today's powertrains are becoming more and more complex due to the increasing number of gear box types requiring gearshift patterns like conventional (equipped with GSI) and automatic-manual transmissions (AT, AMT), double clutch and continuous variable transmissions (DCT, CVT). This increasing variety of gear boxes requires a higher effort for the overall optimization of the powertrain. At the same time, it is necessary to assess the impact of different powertrains and control strategies on CO₂ emissions very early in the development process. The optimization of Gear Shift Patterns (G.S.P.) has to fulfill multiple constraints in terms of objective customers' requirements, like driveability, NVH, performance, emissions and fuel consumption. For these reasons, RENAULT and AVL entered an engineering collaboration in order to develop a dedicated simulation tool: CRUISE GSP.
2011-04-12
Technical Paper
2011-01-0392
Dongxu Li, Kumaraswamy Hebbale, Chunhao Lee, Farzad Samie, Chi-Kuan Kao
Automobile drivers/passengers perceive automatic transmission (AT) shift quality through the torque transferred by transmission output shaft, so that torque regulation is critical in transmission shift control and etc. However, since a physical torque sensor is expensive, current shift control in AT is usually achieved by tracking a turbine speed profile due to the lack of the transmission output torque information. A direct torque feedback has long been desired for transmission shift control enhancement. This paper addresses a “virtual” torque sensor (VTS) algorithm that can provide an accurate estimate on the torque variation in the vehicle transmission output shaft using (existing) speed sensors. We have developed the algorithm using both the transmission output speed sensor and anti-lock braking system speed sensors. Practical solutions are provided to enhance the accuracy of the algorithm. The algorithm has been successfully implemented on both FWD and RWD vehicles.
2011-04-12
Technical Paper
2011-01-0391
Quan Zheng, Bruce Church, Ken Defore
Electro-hydraulic actuation has been used widely in automatic transmission designs. With greater demand for premium shift quality of automatic transmissions, higher pressure control accuracy of the transmission electro-hydraulic control system has become one of the main factors for meeting this growing demand. This demand has been the driving force for the development of closed loop pressure controls technology. This paper presents the further research done based upon a previously developed closed loop system. The focus for this research is on the system requirements, such as solenoid driver selection and system latency handling. Both spin-stand and test vehicle setups are discussed in detail. Test results for various configurations are given.
2010-04-12
Journal Article
2010-01-1314
Erik Hellström, Jan Åslund, Lars Nielsen
Hybridization and velocity management are two important techniques for energy efficiency that mainly have been treated separately. Here they are put in a common framework that from the hybridization perspective can be seen as an extension of the equivalence factor idea in the well known strategy ECMS. From the perspective of look-ahead control, the extension is that energy can be stored not only in kinetic energy, but also electrically. The key idea is to introduce more equivalence factors in a way that enables efficient computations, but also so that the equivalence factors have a physical interpretation. The latter fact makes it easy to formulate a good residual cost to be used at the end of the look-ahead horizon. The formulation has different possible uses, but it is here applied on an evaluation of the size of the electrical system. Previous such studies, for e.g.
2010-04-12
Technical Paper
2010-01-1310
Mohamed El-Sayed, Jon Hintz
The ultimate goals for developing hybrid power train systems are improving fuel economy, reducing emissions and providing commercially viable alternative low cost transportation solutions. To achieve these goals, during hybrid system design and development, a well defined set of targets and specifications are needed. These targets and specifications are necessary for optimizing the power train subsystems, components, successful system integration, and the development of proper control system. For developing a set of well defined targets and specifications, especially when dealing with hybrid power train systems, valid and reliable road load data and duty cycle profiles are required. This data is one of the most critical elements in sizing and control of the hybrid system components such as engines, batteries, generators, and motors.
2010-04-12
Technical Paper
2010-01-1311
Maxime Debert, Guillaume Colin, Yann Chamaillard, Michel Mensler, Ahmed Ketfi-cherif, Lino Guzzella
The energy management of a hybrid vehicle defines the vehicle power flow that minimizes fuel consumption and exhaust emissions. In a combined hybrid the complex architecture requires a multi-input control from the energy management. A classic optimal control obtained with dynamic programming shows that thanks to the high efficiency hybrid electric variable transmission, energy losses come mainly from the internal combustion engine. This paper therefore proposes a sub-optimal control based on the maximization of the engine efficiency that avoids multi-input control. This strategy achieves two aims: enhanced performances in terms of fuel economy and a reduction of computational time.
2010-04-12
Technical Paper
2010-01-1308
Yi Gao, Ray Long, Yong Pang, Magnus Lindenmo
With electric vehicles (EVs) and hybrid electric vehicles (HEVs) set to grow in the coming years, design optimizations of electric motors for automotive applications are receiving more attention. Under demanding duty cycles, the moving part within a motor, the rotor, may experience high and varying stresses, which may lead to fatigue failure. Therefore, engineers are facing challenges in designing efficient and durable motors, especially for interior permanent-magnet (IPM) motors, in which the rotors have embedded magnets with small "bridges" of laminated electrical steel to keep the magnets in place. Cost-effective stators and rotors are made from electrical steels, with high magnetic permeability and low power losses. However, national and international standards for electrical steels do not specify mechanical properties. Steel producers would normally state typical mechanical properties only, and no fatigue properties are available in published literature.
2010-04-12
Technical Paper
2010-01-1305
Sanghee Shin, Jonghan Oh, JoungChul Kim, SungWoo Hong
To alleviate vibration of power-train system in hybrid electric vehicle (HEV) is one of the most difficult obstacles that most of engineers would face. The vibration of gear-shifting would be hider by precise synchronization of applied members in gear-shifting process; however, improvement of the vibration by calibrating conventional hydraulic control was limited. To transcend the limitation of hydraulic method, we developed a combined gear-shifting method assisted by motor speed feedback control to synchronize an input speed of transmission with a target input speed exactly. We divided a whole gear-shifting process into the following five phases to combined hydraulic control with motor speed control. In addition, to prevent the additional vibration, motor speed feedback control starts at the second phase and parameters of motor feedback control are categorized by each phases.
2010-04-12
Technical Paper
2010-01-1307
Johann Willberger, Martin Ackerl, Andrés Rojas, Haymo Niederkofler
As the age of crude oil gradually finishes and political arrangements all over the world force a continuous reduction of global carbon dioxide (CO₂) emissions, energy efficiency and energy sustainability become worldwide a major challenge for automotive industry. The ambitious European goal of a fleet average emission for all new cars of 130 g/km CO₂ by 2012 afford an overall energy efficiency increase of the entire powertrain topologies. One way to come up to this challenge is surely the electrification of powertrain systems. Nowadays, hybrid electric vehicles (HEV) represent one of the most promising technologies that combine the advantages of high performance, high fuel efficiency and low emissions in combination with a long operating range. In literature exists lots of investigations concerning the requirements of different powertrain topologies along with the corresponding individual requirements of electric motor types.
2010-04-12
Technical Paper
2010-01-1108
Farzin H. Montazersadgh
Valve lift is of major importance when considering engine performance, valvetrain durability and NVH. Automating valve lift design and optimization is challenging since there are numerous variables that define the profile and many kinematic and dynamic objectives have to be considered. The kinematic and dynamic objectives for engine performance, valvetrain durability and NVH are conflicting which complicates the automation of the process even more. For example, engine performance requires the valve to open and close in a short period of time which means high valve velocity and acceleration, where as valvetrain durability and NVH require lowering valve seating velocity and acceleration for better dynamic control and reduced impact noise. In this study, a tool has been developed to design and optimize valve lift profile without a starting point and based on kinematic and dynamic design constraints.
2010-04-12
Technical Paper
2010-01-0629
Hamid Oral
A patent pending engine control system with torque sensor feedback is described. Upon detecting a loss in traction by means of a torque sensor, engine torque is adjusted via throttle paving the way for improved traction and enhanced stability. The throttle is reduced to a calculated value using engine characteristics, the torque sensor measurement and non-slipping wheel speed information. The advantages of the powertrain torque sensing as opposed to speed sensing are demonstrated thru a case study of a RWD SUV with an open rear differential. Simulations are used to prove the concept while the bandwidths of a number of physical systems contributing to the overall response time are ignored. Therefore the data provided in this paper should be treated relatively comparing speed sensors versus torque sensors. There are a number of engine torque reduction methods faster than throttle control such as spark retard and fuel shutoff.
2010-04-12
Technical Paper
2010-01-0631
Randy Skiles
All-wheel-drive system calibration has traditionally been a time-intensive task requiring substantial staff and vehicle resources. With vehicle developments constantly evolving and typically shortening in duration, using hardware-in-the-loop simulation (HILS) for data calibration will become crucial to ensure accurate results with available staff and vehicle resources. By introducing HILS into the calibration process, external signals can be modeled in the system and used as calculation tools to solve for calibration parameters that historically had to be tuned by hand this increases the efficiency of a calibration engineer's work. Using the HILS method to calculate calibration data for an all-wheel-drive (AWD) electronic control unit (ECU) provides highly accurate results in a reduced amount of time compared to previous data calibration method. Incorporating the HILS method into the calibration process has cut the time of certain data setting techniques by 80%.
2010-04-12
Technical Paper
2010-01-0688
Thang Nguyen, Georg Pelz
This paper considers the verification of non-standard CAN network topologies of the physical layer at high speed transmission rate (500.0Kbps and 1.0Mbps). These network topologies including single star, multiple stars, and hybrid topologies (multiple stars in combination with linear bus or with ring topology) are simulated by using behavior modeling language (VHDL-AMS) in comparison to measurement. Throughout the verification process, CAN transceiver behavioral model together with other CAN physical layer simulation components have been proved to be very accurate. The modeling of measurement environment of the CAN network is discussed, showing how to get the measurement and simulation results well matched. This demonstrates that the simulation solution is reliable, which is highly desired and very important for the verification requirement in CAN physical layer design.
2011-04-12
Technical Paper
2011-01-0147
Marco Zanussi Barreto, Edson Duque
On the last years with automotive evolution, the vehicle internal noise became an important item for all automakers. Vehicles have many source of noise like tires running on road, engine intake and exhaust flows, wind and transmission gear rattle noise focus of this paper. With all noise reduction improvements and new high compression engines, due to high usage of ethanol fuel; transmission gear rattle noise became more evident and it has taken attention from auto companies in the world. Options to improve the transmission gear rattle noise were created focus on reduce the driveline torsional vibration and focus on improve the gears behaviors. The torsional vibration of driveline can be improved applying a clutch disc with torsional damper or applying a dual mass flywheel on engines.
2011-04-12
Technical Paper
2011-01-0150
Eugene Taschuk, Farokh Kavarana, John DeYoung
In recent years, Continuously Variable Transmissions (CVTs) have made significant inroads into passenger cars because of advantages over traditional Automatic Transmissions (ATs) such as improved efficiency, reduced weight and smoother operation. However, from an acceleration sound quality perspective, drivers generally seem to prefer the AT sound over the CVT sound, especially in sub-compact/compact vehicle segment with small displacement engines and cost-conscious sound packaging. Vehicles equipped with ATs maintain a linear relationship between vehicle speed and engine RPM during wide-open throttle (WOT) acceleration that is dictated by fixed gear ratios. Vehicles with CVTs typically rise rapidly to a high engine RPM (near peak engine torque) and then dwell at a constant engine RPM as the vehicle speed continues to increase by varying CVT pulley ratios.
2011-04-12
Technical Paper
2011-01-0148
Hany Ali Sherif, Reda Elkhodary, Amro Roshdy
The aim of this paper is to present two widely used techniques in gearbox diagnostics through implementation of these techniques on a heavy duty truck with two types of local faults, broken teeth and defected bearing. The first technique presented in this study is the stationary STSF (Spatial Transformation of Sound Field) which is based on the measured acoustic signal captured in the nearfield of the operating gearbox. The second technique is the Vibroacoustic technique which is based on the vibration signal picked up on the gearbox surface. The results from acoustic signals were compared with vibration signals. In contrast to Vibroacoustic technique, unless special methods and particular arrangement are used to reconstruct the acoustic field, STSF may suffer from some difficulty and limitations. Also, background noise or any acquisition errors may result in an erroneous reconstruction of the acoustic quantities.
2011-04-12
Technical Paper
2011-01-0149
Dheeraj Lohani, Anand K. Jammulamadaka, Maruthi Rao Dhulipudi
It has been found during the transmission level test that oil pan is a major contributor of noise to the overall noise emanating from transmission. Oil pan being thin and having substantial surface area becomes a significant noise source. Keeping this in view it is very important to study the acoustic behavior of the oil pan. Several computational techniques are available to study the noise characteristics of such structures. Indirect techniques that compute normalized velocity distributions on the surface from frequency response analysis give a quick assessment of sound power of the structure but can't give the Sound Pressure Level (SPL) at microphone locations. Technique such as Boundary Element Method (BEM) can calculate the SPL but are computationally intensive as the size of the model increases. Infinite Element techniques overcome these shortcomings from the way they are formulated.
2011-04-12
Journal Article
2011-01-0699
Darrell Robinette, Michael Powell
A cost effective means of achieving fuel economy gains in conventional powertrain is to utilize a 12 volt start/stop (S/S) system to turn the engine off and on during periods of vehicle idle. This paper presents powertrain integration issues specific to a 12 volt S/S system and the powertrain hardware content and calibration strategies required to execute a 12 volt S/S system for start ability, reduced noise and vibration (N&V) and vehicle launch. A correlated lumped parameter modeling methodology is used to determine engine startup profiles, starter hardware and intake cam park position requirements based upon vehicle level response to the startup event. Optimization of the engine startup is reported for a multitude of powertrain configurations, including transverse and longitudinal arrangements with manual, automatic and dual clutch transmissions.
2010-04-12
Technical Paper
2010-01-1313
Patrick A. Debal, Saphir Faid, Laurent Tricoche, Steven Bervoets
In 2007 Punch Powertrain started the development of a full hybrid powertrain concept based on its CVT. A performance and efficiency analysis proved that a post-configuration offered the best solution. In parallel to the mechanical and electrical development an advanced, Matlab/Simulink® simulation system was established. A robust powertrain strategy was developed and implemented into the simulation system. Results show a potential of 30% to 70% fuel efficiency improvement depending on the cycle (type approval and real-world cycles). A higher saving potential is possible as a plug-in. The fuel efficiency improvement is reached while meeting other important targets. First of all, the powertrain cost premium needs to match the saving. Next to keeping the transmission cost under control the electric drive technology and the batteries are cornerstones of the powertrain development. A dedicated switched reluctance electric motor/generator is developed at a partner.
2010-04-12
Technical Paper
2010-01-0751
Smita Shivle, A. V. Murthy
Firewall of a car separates the engine compartment from the cabin and acts as a barrier for engine noise entering the passenger compartment. Hence noise transmission through the firewall plays an important role in determining the interior noise of a car. Noise Reduction measurement technique is useful to evaluate existing and potential acoustic treatments of the firewall of a car. This paper presents two systematic measurement approaches for quantifying the acoustic performance of firewall insulation materials across the firewall of a car. First a Volume Velocity Source was placed in the passenger compartment and noise reduction was measured across the firewall with different configurations of firewall acoustic treatments. Similar exercise was repeated by installing an actual vehicle firewall in a sound transmission loss suite and measuring the noise reduction across the firewall.
2010-04-12
Technical Paper
2010-01-0817
Frank J. Falcone, Jim Burns, Douglas J. Nelson
This paper covers the development of a closed loop transaxle synchronization algorithm which was a key deliverable in the control system design for the L3 Enigma, a Battery Dominant Hybrid Electric Vehicle. Background information is provided to help the reader understand the history that lead to this unique solution of the input and output shaft synchronizing that typically takes place in a manual vehicle transmission or transaxle when shifting into a gear from another or into a gear from neutral when at speed. The algorithm stability is discussed as it applies to system stability and how stability impacts the speed at which a shift can take place. Results are simulated in The MathWorks Simulink programming environment and show how traction motor technology can be used to efficiently solve what is often a machine design issue. The vehicle test bed to which this research is applied is a parallel biodiesel hybrid electric vehicle called the Enigma.
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