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IC engine internal cooling system modelling using 1D-CFD methodology

FCA Engineering India Pvt., Ltd.-Dhananjay Sampat Autade, Amit Kumar, Tharunnarayanan Arthanari, Vaibhav Patil, Kamalakannan J
FCA US LLC-Fu-Long Chang
  • Technical Paper
  • 2020-01-1168
To be published on 2020-04-14 by SAE International in United States
Internal combustion engine gets heated up due to continuous combustion of fuel. To keep engine working efficiently and prevent components damage due to very high temperature, the engine needs to be cooled down. Based on power output requirement and provision for cooling system, every engine has it’s unique cooling system. Liquid based cooling systems are majorly implemented in automobile. It’s important to keep in mind that during design phase that, cooling the engine will lower the power to fuel consumption ratio. Therefore, during lower ambient conditions, the cooling system should be able to uniformly increase the temperature of the engine components, engine oil and transmission oil. This is achieved by circulating the coolant through cooling jacket, engine oil heater and transmission oil heater, which will be heated by the combustion heat. The objective of this study is to build a steady state 1D-model of cooling system; comprising of water pump, cooling jacket, engine head, thermostat, radiator, cabin heater, engine and transmission oil heaters with plumbing system. This 1D model is used to simulate vehicle drive…
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Energy Efficient Maneuvering of Connected and Automated Vehicles

Southwest Research Institute-Sankar Rengarajan, Scott Hotz, Jayant Sarlashkar, Stanislav Gankov, Piyush Bhagdikar, Michael C. Gross, Charles Hirsch
  • Technical Paper
  • 2020-01-0583
To be published on 2020-04-14 by SAE International in United States
Onboard sensing and external connectivity using Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I) and Vehicle-to-Everything (V2X) technologies will allow a vehicle to "know" its future operating conditions with some degree of certainty, greatly narrowing prior information gaps. The increased development of such Connected and Automated Vehicle (CAV) systems, currently used mostly for safety and driver convenience, presents new opportunities to improve the energy efficiency of individual vehicles. The NEXTCAR program is one such initiative by the Advanced Research Projects Agency – Energy (ARPA-E) to developed advanced vehicle dynamics and powertrain control technologies that leverage such connected information streams. Southwest Research Institute (SwRI) in collaboration with Toyota and University of Michigan is currently working on improving energy consumption of a Toyota Prius Prime 2017 by 20%. This paper provides an overview of the various algorithms that have been developed to achieve the energy consumption target. A breakdown of how individual algorithms contribute to the overall target is presented. The team built a specialized test-bed called CAV dynamometer that integrates a traffic simulator and a hub dynamometer for testing the…
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Investigation of the Effect of Tire Deformation on Open-Wheel Aerodynamics

Graz University of Technology-Philipp Eder, Cornelia Lex
U.A.S. Graz-Thomas Gerstorfer, Thomas Amhofer
  • Technical Paper
  • 2020-01-0546
To be published on 2020-04-14 by SAE International in United States
This paper introduces a finite element (FE) approach to determine tire deformation and its effect on open-wheeled racecar aerodynamics. In recent literature the tire deformation was measured optically using cameras during wind tunnel testing. Combined loads like accelerat-ing at corner exit are difficult to reproduce in wind tunnels and would require several camer-as to measure the tire deformation. In contrast, an FE approach is capable of determining the tire deformation in combined load states accurately and additionally provides the possibility to vary further parameters, for example, the coefficient of friction. The FE tire model was validated using stiffness measurements, contact patch measurements and steady-state cornering measurements on a flat belt tire test rig. The deformed shape of the FE model was used in a computational fluid dynamics (CFD) simulation. A sensitivity study was created to determine the effect of the tire deformation on aerodynamics for un-loaded, purely vertically loaded and combined vertical, lateral and longitudinal forces. In addition, the influence of these three tire deformations was investigated in a CFD study using a full vehicle…
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A Co-Simulation Platform for Powertrain Controls Development

Hyundai-Kia America Technical Center Inc.-Shihong Fan, Yong Sun, Jason Hoon Lee, Jinho Ha
  • Technical Paper
  • 2020-01-0265
To be published on 2020-04-14 by SAE International in United States
With the advancement of simulation software development, the efficiency of vehicle and powertrain controls research and development can be significantly improved. Traditionally, during the development of a new control algorithm, dyno or on-road testing is necessary to validate the algorithm. Physical testing is not only costly, but also time consuming. In this study, a virtual platform is developed to reduce the effort of testing. To improve the simulation accuracy, co-simulation of multiple software is suggested as each software specializes in certain area. The Platform includes Matlab Simulink, PTV Vissim, Tass Prescan and AVL Cruise. PTV Vissim is used to provide traffic environment to PreScan. PreScan is used for ego vehicle simulation and visualization. Traffic, signal and road network are synchronized in Vissim and PreScan. Powertrain system is simulated in Cruise. MATALB/Simulink serves as master of this co-simulation, and integrates the different software together. It also includes human driver model and a powertrain control function. An ADAS-ISG (Idle Stop and Go) powertrain control algorithm is implemented in Simulink and tested by using the platform under different…
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Scalable Simulation Environment for Adaptive Cruise Controller Development

The University Of Alabama-David Barnes, Jared Folden, Hwan-Sik Yoon, Paulius Puzinauskas
  • Technical Paper
  • 2020-01-1359
To be published on 2020-04-14 by SAE International in United States
In the development of an Adaptive Cruise Control (ACC) system, a model-based design process uses a simulation environment with models for sensor data, sensor fusion, ACC, and vehicle dynamics. Previous work has sought to control the dynamics between two vehicles both in simulation and in empirical testing environments. This paper outlines a new modular simulation framework for full model-based design integration, to iteratively design ACC systems. The simulation framework uses physics-based vehicle models to test ACC systems in three ways. The first two are Model-in-the-Loop (MIL) testing, using scripted scenarios or Driver-in-the-Loop (DIL) control of a target vehicle. The third testing method uses collected test data replayed as inputs to the simulation to additionally test sensor fusion algorithms. The simulation framework uses 3D visualization of the vehicles and implements mathematical driver comfortability models to better understand the perspectives of the driver or passenger. The addition of a high-fidelity vehicle plant model provides energy consumption and emissions predictions for autonomous, conventional vehicles or hybrid electric vehicles (HEV) in realistic driving scenarios. Finally, the simulations are run…
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Virtual Verification of Wrecker Tow Requirements

Ford Motor Company-Majid Tabesh, Steven Foster, Sethuprasant Boomipaulraj, Arthur Gariepy, Jim Alanoly
  • Technical Paper
  • 2020-01-0766
To be published on 2020-04-14 by SAE International in United States
Under various real world scenarios, vehicles can become disabled and require towing. OEM’s allow a few options for vehicle wrecker towing that include wheel lift tow using a stinger or towing on a flatbed. These methods entail multiple loading events that need to be assessed for damage to the towed vehicle. OEMS have several testing and evaluation methodologies in place for those scenarios with majority requiring physical vehicle prototypes. Recent focus to reduce product development time and cost has replaced the need for prototype testing with analytical verification methods. In this paper, the CAE method involving multibody dynamic simulation (MBS) as well as finite element analysis (FEA) of vehicle flatbed operation, winching onto a flatbed and stinger-pull towing methods are discussed. The simulations evaluate and address events such as bumper and underbody parts impact with the ground, subframe impact with the stinger arm, chain loading on the body, as well as winch cable contact with underbody parts. MBS-FEA co-simulations appear to be computationally expensive and, more importantly, target only a specific vehicle configuration and loading…
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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 UB80E front wheel drive 8-speed automatic transmission was benchmarked to determine the losses in operation. The transmission was installed in an engine dynamometer test cell equipped with the 4-cylinder engine from the 2018 Toyota Camry and inline torque transducers to measure transmission loads. A series of tests were conducted to determine the losses associated with the transmission operation, including transmission torque loss in each gear, torque converter K factor, neutral “coastdown” losses, idle torque, and oil temperature effects. The transmission benchmark data and associated engine data were used as inputs to EPA’s Advanced Light-duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model. The ALPHA model simulated the GHG emissions from the 2018 Toyota Camry containing this engine and transmission, and the results were compared to vehicle chassis dynamometer test to validate the model. The torque loss map for the Toyota UB80E was then compared to other benchmarked transmission…
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Decision Making and Trajectory Planning of Intelligent Vehicle’ s Lane-changing Behavior on Highways under Multi-objective Constrains

Wuhan University of Technology-Linzhen Nie, Zhishuai Yin, Haoran Huang
  • Technical Paper
  • 2020-01-0124
To be published on 2020-04-14 by SAE International in United States
Discretionary lane-changing is commonly seen in highway driving. Intelligent vehicles are expected to change lanes discretionarily for better driving experience and higher traffic efficiency. This study proposes to optimize the decision making and trajectory planning process so that intelligent vehicles make lane changes not only with driving safety taken into account, but also with the goal to improve driving comfort as well as to meet the driver’ s expectation. The mechanism of how various factors contribute to the driver’s intention to change lanes is studied by carrying out a series of driving simulation experiments, and a Lane-changing Intention Generation (LIG) model based on Convolutional Neural Network (CNN) is proposed. The inputs of the CNN are data fragments of several influence factors including the relative speed and the distance between the subject vehicle and the preceding vehicles in current lane and both sides of the lane, and the type of the preceding vehicles in current lane and both sides of the lane, the average speed of the left and right traffic flow, the in a certain…
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PHEV hybrid vehicle system efficiency and battery aging optimization using A-ECMS based algorithm

FCA USA LLC-Yang Liang, Sandeep Makam
  • Technical Paper
  • 2020-01-1178
To be published on 2020-04-14 by SAE International in United States
Minimizing lithium ion battery aging and maximizing overall system efficiency are key engineering design objectives for plug-in electric hybrid vehicles (PHEVs). To quantitatively optimize the aging and system efficiency, an Adaptive Equivalent Consumption Minimization Strategy (A-ECMS) based optimization method is implemented within vehicle simulation code. Battery charge and discharge cycling is modeled using equivalent circuit modeling techniques where circuit parameters are updated based on estimated aging effects. These aging effects are predicted through a so-called single particle model wherein particle interactions are neglected, and solid electrolyte interface (SEI) layer aging is predicted for graphite anode. The proposed aging model is calibrated against available battery aging data for similar batteries. Steady state capacity fade map under given environmental conditions and various battery states of charge and current levels are predicted. A battery capacity fade map is generated, and then used in the AECMS optimization function to adjust aggressiveness of the PHEV power split decisions. The results of a single objective (pure efficiency based), and a multi-objective (battery aging and efficiency are weighted to form an objective…
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Understanding How Rain Affects Semantic Segmentation Algorithm Performance

Mississippi State Univ-John Ball
Mississippi State University-Suvash Sharma, Chris Goodin, Matthew Doude, Christopher Hudson, Daniel Carruth, Bo Tang
  • Technical Paper
  • 2020-01-0092
To be published on 2020-04-14 by SAE International in United States
Research interests in autonomous driving have increased significantly in recent years. Several methods are being suggested for performance optimization of autonomous vehicles. However, weather conditions such as rain, snow, and fog may hinder the performance of autonomous algorithms. It is therefore of great importance to study how the performance/efficiency of the underlying scene understanding algorithms vary with such adverse scenarios. Semantic segmentation is one of the most widely used scene-understanding techniques applied to autonomous driving. In this paper, we study the performance degradation of several semantic segmentation algorithms caused by rain for off-road driving scenes. Given the limited availability of datasets for real-world off-road driving scenarios that include rain, we utilize two synthetic datasets. The first dataset is a pure synthetic rainy dataset which considers the rain droplets on a camera lens, which is suitable for an autonomous vehicle with outside-mounted cameras. This data is generated by the MAVS simulator. In the second dataset, we take good-weather imagery and artificially incorporate rain streaks. By investigating different simulated rain rates, we quantify the performance of such…