The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Automatic transmissions
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Reverse Engineering Method for Powertrain Parameters Characterization Applied to a P2 Plug-In Hybrid Electric Vehicle with Automatic Transmission

FEV Group GmbH-Alessandro Perazzo
Politecnico di Torino-Enrico Galvagno, Federico Millo, Giuseppe DiPierro, Mauro Velardocchia, Gianluca Mari
  • Technical Paper
  • 2020-37-0021
To be published on 2020-06-23 by SAE International in United States
Over the next decade, CO2 legislation will be more demanding and the automotive industry has seen in vehicle electrification a possible solution. This has led to an increasing need for advanced powertrain systems and systematic model-based control approaches, along with additional complexity. This represents a serious challenge for all the OEMs. This paper describes a novel reverse engineering methodology developed to estimate relevant but unknown powertrain data required for fuel consumption-oriented hybrid electric vehicle modelling. The main estimated quantities include high-voltage battery internal resistance, electric motor and transmission efficiency maps, torque converter and lock-up clutch operating maps, internal combustion engine and electric motor mass moment of inertia, and finally front/rear brake torque distribution. This activity introduces a list of limited and dedicated experimental tests, carried out both on road and on a chassis dynamometer, aiming at powertrain characterization thanks to a suitable post-processing algorithm. In this regard, the methodology was tested on a P2 architecture Diesel Plug-in HEV equipped with a 9-speed AT. voltage and current sensors are used to measure the electrical power exchanged…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A study on the effect of different glasses and its properties on vehicle cabin during soaking at hot ambient conditions using 1D simulation

FCA Engineering India Pvt., Ltd.-Karthik Subramanian, Prakashbabuji Danapalan, Saravanan Sambandan
FCA US LLC-Murali Govindarajalu
  • Technical Paper
  • 2020-01-0956
To be published on 2020-04-14 by SAE International in United States
Increase in traffic conditions and global increase in the ambient temperature during the summer season, heat load in the vehicle cabin is also increasing, creating a huge thermal discomfort for the passengers. There are two scenarios in which these adverse conditions can be a problem, one is when driving the vehicle in traffic condition and another one is when the vehicle is parked in the open sun both during the summer season. While for the first scenario, at least the air conditioner can be switched on, for the soaking scenario the cabin temperature can reach alarming levels which may have serious discomfort and health effects on the human entering vehicle. Although there are options of remote switching on of air conditioners, they are restricted to vehicles having an automatic transmission only. Considering the different parts of cabin, the glasses occupy majority of the portion which is exposed to the sunlight and that transmit the heat directly into the cabin, which in turn is absorbed by different materials resulting in alarming temperature levels in cabin when…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Benchmarking a 2018 Toyota Camry UB80E Eight-Speed Automatic Transmission

US Environmental Protection Agency-Andrew Moskalik, Mark Stuhldreher, John Kargul
  • Technical Paper
  • 2020-01-1286
To be published on 2020-04-14 by SAE International in United States
As part of the U.S. Environmental Protection Agency’s (EPA’s) continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, a 2018 Toyota Camry front wheel drive eight-speed automatic transmission was benchmarked. The benchmarking data were used as inputs to EPA’s Advanced Light-duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model to estimate GHG emissions from light-duty vehicles.ALPHA requires both detailed engine fuel consumption maps and transmission torque loss maps. EPA’s National Vehicle and Fuels Emissions Laboratory has developed a streamlined, cost-effective in-house method of transmission testing, capable of gathering a dataset sufficient to characterize transmissions within ALPHA. This testing methodology targets the range of transmission operation observed during vehicle testing over EPA’s city and highway drive cycles.With this method, the transmission is tested as a complete system, as opposed to disassembling the transmission components and testing each separately. This paper describes the benchmarking process used to gather transmission data and the test results obtained. A UB80E eight-speed automatic transmission from a 2018 Toyota Camry was installed in an engine dynamometer test…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Gear Shifting Indication Strategy of Eco-driving Vehicle

Jiangsu University-Nannan Hu
Jiangsu University-Ren He
  • Technical Paper
  • 2020-01-0966
To be published on 2020-04-14 by SAE International in United States
The current indication strategy of gear shifting indication system for manual transmission vehicles is developed based on the gear shifting strategy of the automatic transmission. In this paper, the driving data of several automatic transmission and manual transmission vehicles are collected. It is found that the shifting frequency of automatic transmission vehicles is significantly higher than that of manual transmission vehicles, which increases the fatigue of drivers. Aiming at this problem, an interval algorithm of gear shifting indication strategy is proposed based on the fuel consumption rate of engine in this paper. The strategy uses genetic algorithm to process the data of fuel consumption rate, finding the maximum and minimum values in the interval of torque and engine speed, and then the interval algorithm is adopted to transform the search of least fuel consumption value into the seeking of optimal interval to avoid the shifting busyness caused by the sudden change of the data of fuel consumption rate. The model of gear shifting indication strategy is established in Matlab/Simulink. Gear shifting tolerance is defined and…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

An LQR Approach of Automatic Transmission Upshift Control Including Use of Off-Going Clutch within Inertia Phase

Ford Motor Company-Vladimir Ivanovic, Yijing Zhang, Yuji Fujii
University of Zagreb-Ivan Cvok, Josko Deur
  • Technical Paper
  • 2020-01-0970
To be published on 2020-04-14 by SAE International in United States
This paper considers using linear quadratic regulation (LQR) for multi-input control of the Automatic Transmission (AT) upshift inertia phase. The considered control inputs include the transmission input/engine torque, oncoming clutch torque, and traditionally not used off-going clutch torque. Use of the off-going clutch has been motivated by discussed Control Trajectory Optimization (CTO) results demonstrating that employing the off-going clutch during the inertia phase along with the main, oncoming clutch can improve the upshift control performance in terms of the shift duration and/or comfort by trading off the transmission efficiency and control simplicity to some extent. The proposed LQR approach provides setting an optimal trade-off between the conflicting criteria related to driving comfort and clutches thermal energy loss. It ensures tracking a linear-like profile of oncoming clutch slip speed reference, which was found to be nearly optimal based on control trajectory optimization results. A special attention is given on proper implementation of nonlinear energy loss term through LQR cost function cross term and using a clipped optimal control approach to provide that the clutches (described as…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

An Intuitive Derivation of the Dual-Clutch Model for Clutch Shift Dynamics

FCA US LLC-Pradeep Attibele
  • Technical Paper
  • 2020-01-0433
To be published on 2020-04-14 by SAE International in United States
There are several commercial off-the-shelf software available to study transmission and driveline dynamics. Many of these software require a faithful representation of the transmission topology in order to carry out the analyses. This approach utilizes several redundant degrees of freedom which may not be necessary for studying low frequency (<~30 Hz) dynamics and may be computationally inefficient. The dual-clutch model has been proposed as a generic 2-DOF model that overcomes some of these drawbacks. In this paper, the dual-clutch model is initially derived from first principles, starting with the equations of motion for a planetary automatic transmission. The model coefficients - the inertia matrix and the matrix of clutch gains - are then derived using a more intuitive approach and compared to the model derived from first principles.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Parameter Optimization of Two-Speed AMT Electric Vehicle Transmission System

Wuhan University of Technology-Jian Cui, Gangfeng Tan, Jia'ao Feng, Zhongpeng Tian, Philip Agyeman
  • Technical Paper
  • 2020-01-0435
To be published on 2020-04-14 by SAE International in United States
At present, many electric vehicles are often equipped with only a single-stage final drive. Although the single-stage speed ratio can meet the general driving requirements of electric vehicles, if the requirements of the maximum speed and the requirements for starting acceleration or climbing are met at the same time, the power demand of the drive motor is relatively large, and the efficient area of the drive motor may be far away from the operating area corresponding to daily driving. If the two-speed automatic transmission is adopted, the vehicle can meet the requirements of maximum speed, starting acceleration and climbing at the same time, reduce the power demand of the driving motor, and improve the economy under certain power performance. This is especially important for medium and large vehicles. Therefore, this paper considers that the working torque and speed of the motor can be changed by optimizing the speed ratio of the transmission and changing the gear position so that the motor can work more in the high-efficiency zone. Taking an electric logistics vehicle with a…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Classification of Time Series Measurement Data for Shift Control of Automatic Transmission of Vehicles Using Machine Learning Techniques

Aisin AW Co., Ltd.-Yusuke Morikawa, Yasuhiro Ishihara, Taku Akita, Takanori Ide, Noriyuki Miyake, Eiji Moriyama
RIKEN AIP-Hiroshi Nakagawa, Yasuo Tabei
  • Technical Paper
  • 2020-01-0260
To be published on 2020-04-14 by SAE International in United States
An efficient approach to classify time series physical measurement data of shift control of automatic transmission for vehicles is presented. Comfortable acceleration is the essential factor of today’s vehicles. Shift control of automatic transmission of vehicles directly contributes to the comfortable acceleration. Since calibration of automatic transmission of vehicles is time consuming task for expert engineers, the development of autonomous calibration is desired to reduce product development period in today’s competitive automobile market. In the stage of product development, it is difficult to obtain a large amount of physical measurement data. Therefore, we need to develop machine learning method for limited amount of data. For this purpose, we develop the method to classify time series measurement data of shift control of automatic transmission of vehicles. We use support vector machine (SVM) as a machine learning technique. Features, used by SVM, of time series measurement data of shift control of automatic transmission of vehicles is selected by expert engineers. In addition, the computation is too heavy to explore the optimal value of the high dimensional parameter…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Hybrid Optimization Methodology for Flexplate of Automatic Transmission

Mahindra & Mahindra Ltd.-Vadivazhagan Gandhi, Vivek Yadav, Karthikeyan K, Anand Bidre
  • Technical Paper
  • 2020-01-0916
To be published on 2020-04-14 by SAE International in United States
For Automatic transmission application, crankshaft torque is transferred to torque converter through flex plate. As the flex plate has no functional requirement of storing energy as in case of Manual Transmission (MT) flywheel, flex plate design can be optimized to great extent. Flex plate structure must have compliance to allow the axial deformation of torque convertor due to ballooning pressure generated inside the converter. Flex plate experiences dynamic torque and centrifugal forces due to high rotational speed. It should have compliance to accommodate the assembly misalignments with torque convertor in both axial and radial directions. In this paper, sequential and hybrid optimization techniques are described to optimize the flex plate design with stress, stiffness and mass as design constraints. The load path, corrugation length and axial stiffness of flex plate captured accurately using this hybrid optimization. The variation of shape, size, orientation and number of holes are based on the load path and axial stiffness of flex plate. The results show that 35 % of weight reduction is achieved with original design and it meets…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Launch and Lock with Multi-input Multi-Output Converter Control

Ford Motor Company-Yang Xu, Weitian Chen, Stuart Ford, Pinzhi Liu, Edward Dai, Bret Keller, Hong Jiang
  • Technical Paper
  • 2020-01-0262
To be published on 2020-04-14 by SAE International in United States
A torque converter is a type of fluid coupling device used to transfer engine power to the gearbox and driveline. A bypass clutch equipped in a torque converter assembly is a friction element which when fully engaged, can directly connect the engine to the gearbox. The torque converter is an important launch device in an automatic transmission which decouples engine speed from gearbox input speed while provides torque multiplication to drive the vehicle. During partial pedal launch, it is desired to engage the bypass clutch early and reduce the converter slippage in order to reduce power loss and achieve better fuel economy. However, engaging the bypass clutch early and aggressively may disturb the wheel torque and cause an unpleasant driving experience. This paper describes a multi-input multi-output (MIMO) control method to coordinate both engine and converter bypass clutch to simultaneously deliver desired wheel torque and reduce converter slippage. This control method leverages a feedforward control developed with a standard converter hydrodynamic model and a LQR feedback control. It considers the desired gearbox input torque and…