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Optimization of Matching Between Mechanics and Thermodynamics – Approach for Engine Efficiency Improvement

American Bureau of Shipping (ABS)-Changhua He
Heihe Technology Inc-Yuanping Zhao
  • Technical Paper
  • 2020-01-0799
To be published on 2020-04-14 by SAE International in United States
The relationship between engine mechanics and thermodynamics is investigated in this paper. By means of numerical simulation, the inherent mismatching between the mechanics behaviors and the thermodynamic process in internal combustion engines is revealed, which is believed to be the main limiting factor of energy efficiency for the engines available in the current market. A design concept is proposed for engine efficiency improvement - Optimization of matching between engine mechanics and thermal dynamics. A parameter of Matching Gain is defined for quantifying engine efficiency improvement by comparing with a baseline engine. Several case studies have been conducted toward the actual designs in the history of engine development. The reasons for positive gains achieved as well as for negative results obtained are interpreted with the matching concept. Based on the results unveiled by this approach, it is reasonable to predict that an ideal engine with Optimal Matching Between Mechanics and Thermodynamics exists. The matching concept could be used as a guideline for engine efficiency improvement. A concept engine design with the matching approach is under development.
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Fatigue life Prediction of HVAC pipe assembly for measured powertrain load by virtual simulation

FCA Engineering India Pvt Ltd-Sathish Kumar Pandi, C Elango, Kameswara rao Appana, Roshan N. Mahadule, DivaKaruni Murali Krishna
  • Technical Paper
  • 2020-01-0188
To be published on 2020-04-14 by SAE International in United States
Structural durability of automotive components is one of the key requirements in design and development of today’s automobiles. Virtual simulations are used to estimate component durability to save the cost and time required to build the components and testing. The objective of this work is to find the service life of automotive HVAC pipe assembly by calculating cumulative fatigue life for operation under actual powertrain load conditions. Modal transient response analysis is performed using MSC-Nastran with the measured powertrain load time history. Strain based fatigue life analysis is carried out in n-code using modal superposition method (MSM). The estimated fatigue life was compared with the physical test results. This paper also explains the root cause of low fatigue life on pipe assembly and provide the solution. Keywords: Durability, HVAC Pipe, Powertrain, Modal Transient, Fatigue Life
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Review and Assessment of Multiaxial Fatigue Limit Models

FCA Canada Inc-shiping zhang
FCA US LLC-Sean McKelvey, Eniyavan Subramanian, Yung-Li Lee
  • Technical Paper
  • 2020-01-0192
To be published on 2020-04-14 by SAE International in United States
The purpose of this paper is to provide a comparison of multiaxial fatigue limit models and their correlation to experimental data. This paper investigates equivalent stress, critical plane and invariant based multiaxial fatigue models. Several methods are investigated here and are compared based on their ability to predict multiaxial fatigue limits from data published in literature. The equivalent stress based LTJ model, with its ability to account for non-proportional loading, provides very accurate predictions of the fatigue limit under multiaxial loading. This accuracy comes from the model constant which is calculated based on multiaxial fatigue data. This is the only model investigated that requires multiaxial fatigue testing to generate the model parameters. All other models rely on uniaxial test results. Of the five stress based critical plane approaches investigated, the model proposed by Susmel and Lazzarin shows the greatest correlation with the multiaxial fatigue limit data. Overall, the invariant based prismatic hull method has the best agreement with the data found in literature. Additionally, a new critical plane model has been proposed. This new model…
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Safety assurance concepts for automated driving systems

University of Melbourne-Stuart Ballingall, Majid Sarvi, Peter Sweatman
  • Technical Paper
  • 2020-01-0727
To be published on 2020-04-14 by SAE International in United States
Automated Driving Systems (ADSs) for road vehicles are being developed that can perform the entire dynamic driving task without a human driver in the loop. However, current regulatory frameworks for assuring vehicle safety may restrict the deployment of ADSs that can use machine learning to modify their functionality while in service. A review was undertaken to identify and assess key initiatives and research relevant to the safety assurance of adaptive safety-critical systems that use machine learning, and to highlight assurance concepts that could benefit from further research. The primary objective was to produce findings and recommendations that can inform policy and regulatory reform relating to ADS safety assurance. Due to the almost infinite number and combination of scenarios that an ADS could encounter, the review found much support for concepts that involve the use of simulation data as virtual evidence of safety compliance, with suggestions of a need to assure simulation tools and models. Real-world behavioural competency testing was also commonly proposed, although noting this concept has its limitations. The concept of whole-of-life assurance was…
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A Comparison of Decomposition Constructs for Supporting Modularity in Simulink

FCA Canada Inc., McMaster University-Monika Jaskolka
McMaster University-Vera Pantelic, Alan Wassyng, Mark Lawford
  • Technical Paper
  • 2020-01-1290
To be published on 2020-04-14 by SAE International in United States
The Model-Based Development (MBD) paradigm is widely used for embedded controls development, with MathWorks’ Simulink modelling environment being extensively used in the automotive industry. As production-scale Simulink models are typically large and complex, there exists a need to decompose them properly in order to facilitate their maintainability, understandability, and evolution. MathWorks recommends the use of three constructs for model “componentization” or decomposition: the Subsystem, Library, and Model Reference. However, a recently added construct, the Simulink Function, can also be used for this purpose, while also supporting information hiding due to the construct’s ability to be scoped and encapsulate data. This paper provides an in-depth comparison of these Simulink constructs to fully understand the differences in their reusability, sharing of program state, encapsulation, and code generation, with the goal of facilitating model evolution. An automotive powertrain example is provided to highlight the differences between approaches. Conventions for structuring models are also presented.
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AR projection for driver assistance in autonomous vehicles

Automotive Accessories-Nalinikanth Yerram, Balasubramanian Achuthan
Embedded Systems Software & Security-Srinivas Chandupatla
  • Technical Paper
  • 2020-01-1035
To be published on 2020-04-14 by SAE International in United States
Augmented Reality (AR), which involves the integration of digital information with our physical environment in real-time, has been steadily growing over the past few years, finding its way into multiple areas of our lives. Augmented Reality (AR) in automotive vehicles has contributed to revolutionizing the way passengers and drivers access information, acquire knowledge and integrate into the physical spaces and destinations visited. The studies produced concerning this field are still limited, particularly in the perception of how users adopt technology and what use they make of it. On the other hand, even more limited are the studies that consider the role of stakeholders in the implementation of AR technology. In this paper, we discuss and propose solutions for following ADAS applications using projection unit mounted on board projecting on the windshield. • 5G in your route (signal strength - android applications on HU to detect the signal strength and display it on projection unit)). 5G connectivity help to realize the future of connected cars through higher speeds (up to 10 Gbps), better coverage (capacity expansion…
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Efficient Surrogate-based NVH Optimization of a Full Vehicle Using FRF Based Substructuring

Beta CAE Systems USA Inc-Inseok Park
Oakland Univ-Dimitrios Papadimitriou
  • Technical Paper
  • 2020-01-0629
To be published on 2020-04-14 by SAE International in United States
The computer simulation with the Finite Element (FE) code for the structural dynamics becomes more attractive in the industry since it enables quickly evaluating the dynamic performances of the mechanical products like automobile in development with improved accuracy owing to modern technological advancements. However, it normally takes a prohibitive amount of computation time when design optimization is performed with conducting a dynamic analysis using a large-scale FE model many times. Exploiting Dynamic Structuring (DS) leads to alleviating the computational complexity since DS necessities iterative reanalysis of only the substructure(s) to be optimally designed. In this research, FRF Based Substructuring (FBS) is implemented to realize the benefits of DS for fast single- and multi-objective evolutionary design optimization. Also, Differential Evolution (DE) is first combined with two sorting approaches of NSGA-II and Infeasibility Driven Evolutionary Algorithm (IDEA) for effective constrained single- and multi-objective evolutionary optimization. The effectiveness of the proposed algorithm (NSGA-II/DE-IDEA) is verified using several test functions for constrained single- and multi-objective optimization. To circumvent the need for frequent time-consuming simulation runs, Kriging surrogate models are…
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The GTU – A New Realistic Generic Pickup Truck and SUV Model

Ford Motor Company-Sudesh Woodiga, Kevin Howard, Paul Norman, Neil Lewington, Robert Carstairs, Burkhard Hupertz, Karel Chalupa
  • Technical Paper
  • 2020-01-0664
To be published on 2020-04-14 by SAE International in United States
Traditionally, ground vehicle aerodynamics has been researched with highly simplified models such as the Ahmed body and the SAE model. These models established and advanced the fundamental understanding of bluff body aerodynamics and have generated a large body of published data, however, their application to the development of passenger vehicles is limited by the highly idealized nature of their geometries. To date, limited data has been openly published on aerodynamic investigations of production vehicles, most likely due to the proprietary nature of production vehicle geometry. In 2012, Heft et al. introduced the realistic generic car model ‘DrivAer’ that better represents the flow physics associated with a typical production vehicle. The introduction of the DrivAer model has led to a broad set of published data for both experimental and computational investigations and has proven itself invaluable as a correlation and calibration tool of wind tunnels, the validation of computational fluid dynamics (CFD) codes and increasing the understanding of the fundamental flow physics around passenger vehicles. Automotive sales trends in the United States, published by the Bureau…
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The Review of Vehicle Purchase Restriction in China

Tsinghua Univ-Han Hao, Fuquan Zhao, Zongwei Liu
Tsinghua Univ.-Feiqi Liu
  • Technical Paper
  • 2020-01-0972
To be published on 2020-04-14 by SAE International in United States
In the past two decades, rapidly expanding economy in China led to burst in travel demand and pursuit of quality of life. It further promoted the rapid growth of China's passenger car market. China had already become the largest vehicle sales country, exceeding the U.S. in 2010. By the end of 2018, there had been over 240 million cars in China, with over 200 million passenger cars. The surge of car ownership has also brought a series of problems, like traffic congestion, long commuting time, insufficient parking space, etc. Therefore, some local governments in China introduced vehicle purchase restriction policies to control the growth and gross of vehicle stock. Different cities issued different rules. Lottery and auction mechanisms both exist. There are also differences in classification and licensing of electric vehicles. While, With the recent slowdown of economic development, China's car sales began to decline in 2018, and the trend of 2019 is also not optimistic. As a result, the central government issued document, indicating that it is strictly forbidden to introduce new restrictions on…
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A Novel Supervisory Control and Analysis Approach for Hybrid Electric Vehicles

BorgWarner Inc-Nithin Kondipati, Xiaobing Liu, Sara Mohon, Dmitriy Semenov, John Shutty
  • Technical Paper
  • 2020-01-1192
To be published on 2020-04-14 by SAE International in United States
There are many methods developed over the past decade to solve the problem of energy management control for hybrid electric vehicles. A novel method is introduced in this paper to address the same problem which reduces the problem to a set of physical equations and maps. In simple terms, this method directly calculates the actual cost or savings in fuel energy from the generation or usage of electric energy. It also calculates the local optimum electric power that yields higher electric fuel savings (EFS) or lower electric fuel cost (EFC) in the fuel energy that is spent for driving the vehicle (which in general does not take the system to the lowest engine Brake Specific Fuel Consumption (BSFC)). Based on this approach, a control algorithm is developed which attempts to approach the global optimum over a drive cycle. The main objective of this paper is to introduce the theoretical background and mathematical formulation of EFX (EFS/EFC) metric and explain the development of EFX maps for a specific architecture. Later, these maps are used to develop…