Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 2934
2017-03-28
Technical Paper
2017-01-1107
Christoph Andre Malonga Makosi, Stephan Rinderknecht, Ralf Binz, Frank Uphaus, Frank Kirschbaum PhD
In order to offer a wide range of driving experiences to their customers, original equipment manufacturers implement different driving programs. The driver is capable of manually switching between these programs which alter drivability parameters in the engine control unit. As a result, acceleration forces and gradients are modified, changing the perceived driving experience. Nowadays, drivability is calibrated iteratively through road testing. Hence, the resulting set of parameters is strongly dependent on the individual sentiments of the test engineers. It is shown, that implementing a set of objective criteria offers a way of eliminating personal preferences and sentiment from the drivability calibration process. In combination with the expertise of the testing engineers, the desired vehicle behavior can be transferred into a transient set point sequence to design the acceleration behavior.
2017-03-28
Technical Paper
2017-01-1144
Jongryeol JEONG, Ram Vijayagopal, Aymeric Rousseau
Building a vehicle model with an accuracy sufficient for fuel economy analysis is a time consuming job even with the modern day simulation tools. Getting the right kind of data for modelling a vehicle can itself be challenging. While OEMs advertise the power and torque capability of their engines, the efficiency data for the components or the control algorithms are not usually made available for independent verification. US DOE funds the testing of vehicles at Argonne national lab and this test data is publicly available. Argonne is also the premier DOE laboratory for modelling and simulation of vehicles. By combining these two unique capabilities, a process is developed to automatically develop a model for any conventional vehicle that is tested at Argonne. This paper explain the process of analyzing the publicly available test data and computing the various component parameters from that.
2017-03-28
Technical Paper
2017-01-1142
Vanja Ranogajec, Josko Deur
The ever-present pressure on shortening the development cycles in automotive industry requires further development of numerical methods and software tools in support of those development processes. From the perspective of system dynamics analyses and control system designs, the development of methods that allow for automated generation of computationally efficient mathematical models is of a large interest. In the field of automatic transmissions (AT), automated modeling would ultimately include generation of a full-order, minimum-realization mathematical model directly from an AT schematics. Furthermore, it is of interest to derive a method/tool for automated generation of a reduced-order model for an arbitrary clutch state, which would account for the energy-dependent variables related to locked clutches.
2017-03-28
Technical Paper
2017-01-1631
Weizhe Qian, Henry Zhang
Double Clutch Transmission system becomes more and more popular in vehicles because of the fuel saving performance, cost efficiency and comfortable feeling during gear change. To save fuel consumption, oil pump can be used for oil pressure on demand control. Sensorless control has cost advantage because it removes the motor position sensor. This paper will introduce a technical solution for BLDC (Brushless DC) motor sensorless control for oil pump used in DCT system. To implement sensorless block commutation of BLDC motor, usually Back-emf voltage needs to be compared with a reference voltage. A `zero-crossing point’ of the Back-emf voltage can indicate the rotor position, and hence motor can be controlled without position sensor. Phase feedback pins of Infineon pre-driver device TLE9180 provide these `zero-crossing point’ information based on hardware. The outputs of phase feedback pins are connected to a module CCU6 (capture compare unit6) from 32bit micro-controller Aurix.
2017-03-28
Technical Paper
2017-01-1124
Enrico Galvagno, Mauro Velardocchia
This paper investigates the effect of the powertrain mounting system on the linear and nonlinear torsional dynamical behaviour of a transmission system. To this aim, two dynamic models, namely rigid mounts model and flexible mounts model, are presented and compared, the first considering only the torsional dynamics of the transmission and driveline, the second considering also a 3 degrees-of-freedom powertrain block dynamics. The mechanical coupling and interaction between the powertrain block and transmission system is discussed and formulated. These models are then analysed in terms of vibrational mode shapes, natural frequencies and Frequency Response Functions (FRFs), considering also the sensitivity to the main transmission parameters on the system vibrations.
2017-03-28
Technical Paper
2017-01-1630
Yiu Cheung, Zhijia Yang
It is well known now that a warmed up engine consumes less fuel using stopping and starting compared to idling for a certain period. Since the first stop-start system introduced in 1983, more and more vehicles have been equipped with this automatic engine control system. Recently, it was found that there is strong correlation between engine resting position and engine start time. The utilisation of the synchronization time with the prerequisite of engine stop position prior the engine start request was shown to reduce start times. Hence the position control of an engine during shutdown becomes more significant. This paper presents an experimental study of the positon control of a turbo-charged four-cylinder gasoline engine on a test bed. Various control authorities such as throttle control, alternator control and wastegate control have been investigated and compared.
2017-03-28
Technical Paper
2017-01-1129
Kayoko Kanda
The friction performance of wet clutch for automatic transmission is decided in paper type friction material, separate plate and automatic transmission fluid(ATF). Then we carried out a friction test for the screening of the ATF's additive and found organic sulfur material which was a high coefficient of static friction. A high coefficient of static friction of organic sulfur material is 30% rise, but it changed into a drop. We analyze a friction surface and elucidated the cause of the change.
2017-03-28
Technical Paper
2017-01-1135
Sen Zhou, Bryan Williams
The transmission spinloss has significant influences on the vehicle fuel economy. Transmission output chain may have 10~15% contribution to it. However, the chain spinloss information is very rare. It is challenge to give a good estimation of the chain spinloss. An experimental study was carried out with several transmission output chains and simulated transmission environment in a testing box. The studies build the bases for the chain spinloss modeling and depicted the influences of the speed, the sprocket sizes, the oil levels, the viscosity, the temperatures and the baffle. The kriging was employed for the parameter sensitivity study. The results indicate that the speed, the sprocket width, the oil height and the viscosity are the top influencers depending upon the speed range.
2017-03-28
Technical Paper
2017-01-1119
Fangwu Ma, Ying Zhao, Yongfeng Pu, Jiawei Wang
Gear transmission is one of the most widely used form in mechanical transmission system and plays an important role in Automobile industry. Manufacturing errors, assembly looseness, gear wear issues in gear transmission system may result in backlash of gear, noise and fatigue damage, which seriously affect the efficiency and service life of gear transmission. For the gear transmission assembled, it is of great importance to obtain the desired results monitoring the condition of gear meshing and prevent the occurrence of dangerous situations. How to determine whether there are some issues of gear tooth wear, misaligned bearing, gear eccentricity and backlash and how to define gear sets with problems and find the specific problems which already exist on gear transmission are of great value and significant to ensure the quality and design of product.
2017-03-28
Technical Paper
2017-01-0403
Guangqiang Wu, Huwei WU
Experimental program and considerations, frequency characteristics, subjective and objective sound quality evaluation and prediction model establishment of a certain mass-production SUV (Sport Utility Vehicle, SUV) manual transmission gear rattle phenomenon were analyzed in this paper. Firstly, vehicle experiment schemes, including experimental operating conditions, vibration acceleration sensor and microphone arrangements and especial considerations in experiments, were introduced in detail. Secondly, through coherence analysis in frequency domain and time-frequency analysis in time-frequency domain, broadband characteristics of manual transmission gear rattle vibro-impact and frequency range of 350~4500Hz were concluded on vehicle idling condition and creeping condition.
2017-03-28
Technical Paper
2017-01-1060
Sergei Viktorovich Aliukov
The inertial continuously variable transmissions are mechanical transmissions that are based on the principle of inertia. These transmissions have a lot of advantages. Usually, the design of the inertial continuously variable transmissions consists of inertia pulsed mechanism with unbalanced inertial elements and two overrunning clutches. Dynamics of the transmissions is described by systems of substantial nonlinear differential equations. In general, precise methods of solution for such equations do not exist. Therefore, in practice, approximate analytical and numerical methods must be employed. The main analytical methods employ successive approximation, a small parameter, or power series expansion. Each approach has its advantages and disadvantages. Therefore, we need to compare them in order to select the best method for dynamic study of such kind of transmissions.
2017-03-28
Technical Paper
2017-01-1108
Yulong Lei, Yao Fu, Ke Liu, Li Xingzhong, Zhenjie Liu, Yin Zhang, Xuanyi Fu
Selection of gearshift point plays an important role in the field of automatic transmission technology, which directly affects the vehicle dynamic and economic performance, etc. For stepped automatic transmission, it is generally believed that improving the fuel economy while not compromising the driveability is still a challenging research problem. And the traditional calibration method based on artificial experience widely used at home and abroad suffers from many issues, such as long development cycle, high cost, and real-time fault optimization between vehicle dynamic and fuel economy. In order to designing optimal gearshift strategies for conventional passenger vehicles equipped with stepped automatic transmission, in this paper, the analysis method of vehicle power demand was studied under different environment, different driving intention and different vehicle operating conditions.
2017-03-28
Technical Paper
2017-01-1143
Vladimir Ivanovic, H. Eric Tseng
Modern planetary automatic transmissions are complex reconfigurable dynamic systems. Appropriate mathematical models will enhance the understanding of shift dynamics, the effort of the hardware design optimization, and the efficiency of software development and calibration. This paper focuses on the bond graph model based method for modeling the transmission dynamics. We first summarize bond graph models for the most relevant planetary gear sets (single, double and stepped pinion and Ravigneaux). We then demonstrate how to use these building blocks to construct device-mapping bond graph models of complete planetary transmissions of 6 speed and 10 speed transmissions for RWD. We further describe the procedure of deriving mathematical models based on derived bond graph models. The case with all clutches slipping is considered first and then cases with some clutches locked for so-called reduced order models.
2017-03-28
Technical Paper
2017-01-1120
Kenji Tsutsumi, Yoshitaka Miura, Yusuke Kageyama, Arata Miyauchi
A CVT variator chain system is superior in efficiency to a variator belt system because of its lower internal friction. However, a chain produces more noise than a belt due to the long contact length between the rocker pins and pulley sheaves. This paper focuses on optimization of the link arrangement pattern (pitch sequence) in order to reduce chain noise. The current pitch sequence puts links of different lengths together appropriately and reduces the peak level of 1st-order chain noise by improving noise dispersibility. First, the object function for optimization was defined as the reduction of the peak level of 1st-order chain noise combined with a well-balanced chain noise level of low and high frequency bands. Road noise and wind noise as transmission background noise have the characteristic that they increase as the frequency decreases.
2017-03-28
Technical Paper
2017-01-1116
Tomohiro Tasaka, Nobuyuki Oshima, Shinji Fujimoto, Yuya Kishi
Automatic transmission torque converter is usually used as a power transmission element. As the reason, torque converter is the function of the torque matching and the torque amplification and the engine. This is referred as the fluid performance of torque converter. The fluid performance of torque converter is determined by the blade shape of the torque converter. Therefore it is necessary to predict the fluid performance of the torque converter at the design stage to determine the blade shape, Computational Fluid Dynamics (CFD) analysis is used predict the fluid performance. Generally, time-averaged turbulence models such as K-ε(Reynolds Averaged Navier Stokes (RANS model)) is often used in this CFD analysis. In this RANS model, since the analysis time exists shorter calculation examples is not limited to the torque converter , they are too used for industrial purpose.
2017-03-28
Technical Paper
2017-01-1113
Yulong Lei, Pengxiang Song, Hongpeng Zheng, Yao Fu, Zhenjie Liu, Xuanyi Fu
Hydraulic retarders have been widely used in heavy-duty vehicles because of its advantages such as large braking torque and long operating hours. They can be used instead of service brakes in non-emergency braking conditions and can also reduce frequency and time of driver’s actions in braking process, thereby minimizing heat-related problems. In order to accurately produce braking torque needed for the vehicle in time by using hydraulic retarder, which enable the vehicle to travel stably and safely during downhill driving, aiming at the constant-speed function of hydraulic retarder, the research of constant speed control method is conducted in this paper. The structure and working principle of hydraulic retarder is introduced and the dynamic characteristic is analyzed. And the theoretical model of vehicle and hydraulic retarder are established based on dynamic analysis of the vehicle downhill driving.
2017-03-28
Technical Paper
2017-01-1637
David Cheng
This is a new design for sensor extreme long travel range detection technology especially for clutch master cylinder piston position detection and fork position detection in transmission application to replace PLCD50 platform with simple manufacturing process and high accuracy. The main innovation point includes integrating a ferromagnetic concentrator into sensor module to enhance magnetic flux density at remote area of travel range and applying 3D HALL array with microcontroller for signal post process to guarantee the accuracy of sensor. SPI mode is used for communication between 3D HALL array and microcontroller while a new signal post process method with self-learning calibration is applied in microcontroller algorithm.
2017-03-28
Technical Paper
2017-01-1094
Yusuke Nakade, Atsushi Kamada, Koki Ueno, Mikine Kume, Kouji Sakaguchi
Shift selection devices are desired to be flexible for design and layout, in order to realize the next generation of cockpits for Lexus vehicles. In addition, refined shift operation feelings are also required to be suitable for Lexus vehicles. To meet these demands, the Lexus LC500 has been equipped with a shift-by-wire system, which replaces the mechanical linkage between the shift selector and transmission with electrical signals and an actuator. This shift-by-wire system will be installed in a wide variety of Lexus powertrain lineup, including conventional gas vehicles and hybrid vehicles. Therefore, the next generation shift-by-wire system for Lexus has been developed with high reliability and applicability. This technology will be essential when autonomous driving and autonomous parking systems are realized in the near future.
2017-03-28
Technical Paper
2017-01-1092
Jianbo Lu, Edward Dai, Jonathan Sullivan, Guopeng Hu, Sanghyun Hong, Ryan Baker, Dennis Reed
This paper proposes a road preview based shift schedule optimization for vehicles equipped with automatic transmissions. The road preview considered here is the electronic horizon from digital maps, which include many useful road attributes for the roads ahead including slope, curvature, and speed limit. The optimal shift gear ratios are obtained through applying a hybrid model predictive control approach to multiple powertrain models associated with multiple shift gears so as to improve the vehicle’s real world fuel economy and drivability. The real-world fuel economy optimized by the proposed predictive shift uses the optimal gear ratio in response to slope variations of the road ahead. The drivability improvement focuses on improving the driver’s curve negotiation performance by eliminating back-to-back shift caused shift business. The proposed predictive strategy has been verified in a simulation environment called the VMAPS, developed at Ford.
2017-03-28
Technical Paper
2017-01-1099
Seiji Masunaga, Terufumi Miyazaki, Yohei Habata, Kazuhiko Yamada, Yoshio Hasegawa, Takahiro Kondo, Ichiro Kitaori, Akira Takeichi
Toyota Motor Corporation has developed an innovative 10-speed longitudinal automatic transmission called the Direct Shift-10AT. The Direct Shift-10AT is a significant contributor to the excellent dynamic performance of the Lexus LC500. A wide gear spread with close gear ratios allows for rhythmical shifting, smooth and powerful acceleration from a standing start, along with quiet and relaxed high-speed driving due to low engine speeds. The lock-up area is expanded to a wider range of vehicle speeds (excluding low-speed regions such as when starting off), by the adoption of a multi-plate lock-up clutch, a newly developed torque converter, and a high-precision controller. As a result, the shift control can match the driver’s intended operation more directly because the main cause of the response delay (transient changes in engine speed (flare)) is eliminated. Furthermore, fuel economy is improved due to the adoption of low friction clutches.
2017-03-28
Technical Paper
2017-01-1097
Tomohide Suzuki, Hiroyuki Sugiura, Atsushi Niinomi, Shingo Maezuka, Terufumi Miyazaki, Yohei Habata
Aisin AW (AW) and Toyota Motor Corporation (TMC) have developed a new rear wheel drive (RWD) 10 speed automatic transmission, AWR10L65 (AGA0), suitable for RWD/AWD luxury passenger cars and sports cars. This 10 speed automatic transmission provides enhanced drivability leading to outstanding driver satisfaction. This has been accomplished using a close ratio gear train with optimized gear steps for rhythmic shift changes and quick acceleration. Low rpm lock-up and highly responsive shift changes result in a direct shift feel. This automatic transmission contributes to improved fuel economy by having higher efficiency and lower mass than current 8 speed RWD automatic transmissions.
2017-03-28
Technical Paper
2017-01-1042
Eric J. Passow
Current market demands in conjunction with increased emission legislation's, have OEM’s striving to improve fuel economy and reduce CO2 emissions. One way to meet these demands, is through engine downsizing. Engine downsizing allows for reduced pumping and frictional losses. However, to maintain drivability, specifically in trucks and SUV's, power density increase through the addition of either a turbocharger or supercharger is necessary. Furthermore, engine efficiencies have been improved through reduced engine speed, paired with high gear count transmissions, providing an opportunity for manufactures to achieve desired drivability (strong acceleration coupled with fuel efficient high gears for cruising). With these advancements taken to improve engine/vehicle efficiency, gasoline turbo charge direct injected (GTDI) engines operate at low engine speeds with high torque output.
2017-03-28
Technical Paper
2017-01-1629
Jing Wang, John Michelini, Yan Wang, Michael H. Shelby
Time to torque (TTT) is a quantity used to measure the engine transient torque response. It is referred as the time duration from a full torque command to the time when 95% of maximum torque is achieved. In this work, we seek to control multiple engine actuators in a collaborative way such that the TTT is minimized. We pose the TTT minimization problem as an optimization problem by parameterizing each engine actuator transient trajectory as a Fourier series, followed by minimizing proper cost function with the optimization of those Fourier coefficients. This optimization problem is in general non-convex with unknown structure. To solve the problem in CAE environment, we construct an optimization framework that integrates high-fidelity GT POWER engine model and engine actuators’ Simulink model into modeFrontier computation platform. We conduct simulation study by using this optimization framework on two different turbocharged engines.
2017-03-28
Technical Paper
2017-01-1632
Norihiro Tsukamoto, Tomohiro Chimbe, Tomohiro Asami, Keisuke Ota, Seiji Masunaga
A new shift control system using a model-based control method for stepped automatic transmissions. Using a gear train numerical formula model, the model-based shift control system is constructed using minimum calibration parameters with feedforward and feedback controllers. It also adopts control target values for the input shaft revolution and output shaft torque, thus enabling precise control that provides the most suitable shift feeling in various driving situations and for various vehicle characteristics. Furthermore, the model-based shift control system improves robustness in terms of disturbance elements such as production tolerance, time degradation, and use environment. Toyota has adopted this model-based shift control system in its UA80/UB80 8-speed automatic transmissions for front-wheel-drive vehicles and its AGA0 10-speed automatic transmission for rear-wheel-drive vehicles. This paper describes the details of this model-based shift control system.
2017-03-28
Technical Paper
2017-01-1114
Ramalingam Sivakumar, Srinivasa Prakash Regalla
This paper covers the modelling of an Integrated Prognostics Observer for real-time condition monitoring of the dry clutch system and gearbox used on Automated Manual Transmission (AMT). The real time sensor data of the clutch actuator and gear actuator piston positions are analysed for monitoring the condition of the clutch system and gearbox synchroniser. Original parameters of the new clutch and gearbox hardware are stored in the Electrically Erasable Programmable Read-only Memory (EEPROM) of the AMT controller and the real time data is used by the integrated prognostics observer for assessing the degradation/wear. Clutch slip during torque transmission and the synchronization time are continuously monitored for providing timely alert for re-calibration of the AMT system.
2017-03-28
Technical Paper
2017-01-1110
Muammer Yolga
With the introduction of new regulations on emissions, fuel efficiency and driving cycles, challenges for the powertrains are significantly increasing to a new level. During the transition phase for these new targets, hybrid-electric powertrains are an unquestioned option for short and long-term solutions. Hybridization however, not only brings benefits on these challenging efficiency or emission targets, but also allows numerous new possibilities on controls of different powertrain elements as well as new approaches of design of powertrain elements. A good example is transmissions where, hybridization allows a new transmission type called Dedicated Hybrid Transmission (DHT), which enables to use novel control strategies bringing improved performance, driveability, durability and NVH behavior. This paper focuses on the novel shift strategy where friction clutches do not have to slip.
2017-03-28
Technical Paper
2017-01-1095
Sankar B. Rengarajan, Jayant Sarlashkar, Peter Lobato
Strict government regulation of green house gases, rising corporate average fuel economy standards and high customer expectation of performance have prompted vehicle manufacturers to consider all technology options. Overall efficiency of a vehicle drivetrain can be improved by optimizing component performance – and transmission, regardless of its type, is a key component of the drivetrain. SAE Recommended Practice J1540 specifies test procedures to map torque transmission efficiency and parasitic losses in a manual transmission. The procedure comprises two parts. The first compares input and output torque over a range of speed to determine efficiency. The second measures parasitic losses at zero input torque over a range of speed. As specified in J1540, efficiency of transmissions is routinely measured on a test-stand under steady torque and speed.
2017-03-28
Technical Paper
2017-01-1133
Norman J. Bird, Raunak Bindra, Jacob Klaser
This paper discusses new developments in the field of one-way clutches (OWC). These recent developments involve “Selectable OWC (SOWC)” actuating both hydraulically as well as electrically. The primary focus of this paper is a low-current consuming Electrical SOWC (eSOWC) used in hybrid transmission being designed and developed at Ford Motor Company. Other SOWCs currently being utilized across different applications at Ford are also discussed. Clutching devices represent significant cost, weight, size and drag-loss in automatic transmissions. However, implementation of SOWCs offers the potential to reduce transmission cost, size, weight, and spin loss; eSOWCs may also improve shift quality, reduce shift times, improve shift consistency and reduce OWC-related NVH. In Hybrid applications the electric motor(s) and SOWC create a system that is analogous to a manual transmission synchronizer.
2017-03-28
Technical Paper
2017-01-1128
Yuvraj Y. Gorwade, Anand S. Damami
To ensure a robust, reliable and durable product, predicting useful life of aggregates at the concept stage is a very important aspect in the any product design. This requirement is very much necessary in today's environment, wherein the customer expectations are increasing and allow-able development time for reliable product is decreasing. Clutch is one of the important aggregate in an Automobile having Manual Transmission, which acts like a fuse in the driveline system wherein its wear & tear cannot be avoidable. The performance of Clutch is correlated with its useful life. In this paper, a unique methodology is formulated for the prediction of useful clutch life. Actual field data like warranty, type of failure, etc on a typical utility vehicle platform has been captured for over 3-4 years which have been operating on Indian roads. With the help of data analysis, beta life of clutch, for a given vehicle configuration has been calculated using statistical approach.
2017-03-28
Technical Paper
2017-01-1139
Syeda Faria Mahmud, Shahjada Pahlovy, MASAMITSU KUBOTA, Makoto Ogawa, Norio Takakura
Reduction of drag torque is a crucial demand for improvement of transmission efficiency and fuel economy. In the low speed range, the drag torque at first increases with speed till it reaches a peak point, and then it starts decreasing sharply and finally stays at a minimum level until certain speed limit. Several analytical and simulation models have been presented by the researchers describing the drag torque characteristics at lower clutch speed. However, under certain conditions, the drag torque again starts to rise sharply in the high speed range (6000~10000+ rpm) and even exceeds the peak torque magnitude of low speed. The alarming jump of the drag torque at high rotational speed remains indeterminate till date. In this paper, we presented a simulation model that can predict the high speed torque jump up at different conditions. Simulation result shows that the static pressure decreases very sharply in the oil outlet region as the speed rises beyond 5000 rpm.
Viewing 1 to 30 of 2934