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Video

Monitoring NO2 Production of a Diesel Oxidation Catalyst

2012-01-24
A combination of laboratory reactor measurements and vehicle FTP testing has been combined to demonstrate a method for diagnosing the formation of NO2 from a diesel oxidation catalyst (DOC). Using small cores from a production DOC and simulated diesel exhaust, the laboratory reactor experiments are used to support a model for DOC chemical reaction kinetics. The model we propose shows that the ability to produce NO2 is chemically linked to the ability of the catalyst to oxidize hydrocarbon (HC). For thermally damaged DOCs, loss of the HC oxidation function is simultaneous with loss of the NO2 production function. Since HC oxidation is the source of heat generated in the DOC under regeneration conditions, we conclude that a diagnostic of the DOC exotherm is able to detect the failure of the DOC to produce NO2. Vehicle emissions data from a 6.6 L Duramax HD pick-up with DOC of various levels of thermal degradation is provided to support the diagnostic concept.
Video

High Load HCCI Operation Using Different Valving Strategies in a Naturally-Aspirated Gasoline HCCI Engine

2012-02-16
This session focuses on kinetically controlled combustion. Experimental and simulation studies pertaining to various means of controlling combustion are welcome. Examples are research studies dealing with temperature and composition distribution inside the cylinder and their impact on heat release process. Studies clarifying the role of fuel physical and chemical properties in autoignition are also welcome. Presenter Hanho Yun, General Motors Company
Video

Technical Keynote: Leading in Crazy Times

2012-02-09
Leading during normal times is plenty challenging. Leading in crazy times requires extra understanding and skill. This presentation explores how you and your team can be your best, regardless of what craziness may be going on around your organization, your team members, and you. Presenter Theresa Rich, General Motors Company
Video

OBD Challenges for Plug In Hybrid Electric Vehicles

2012-01-30
Plug-In Hybrid and Extended Range Electric Vehicle's have quickly become the focus of many OEM's and suppliers. Existing regulations and test procedures did not anticipate this rapid adoption of this new technology, resulting in many product development challenges. The lack of clear requirements is further complicated by CARBs consideration of CO2 inclusion in their next light duty OBD regulation. This presentation provides an overview of the regulatory requirements for OBD systems on hybrid vehicles that intend to certify in California. Near term challenges for EREV?s and PHEV?s are discussed, including concerns with the existing denominator and warm-up cycle calculations. Some proposals are made to address these concerns. Presenter Andrew Zettel, General Motors Company
Video

Worldwide OBD

2012-01-30
OBD system requirements were first developed by the California Air Resources Board, the U.S. Environmental Protection Agency, and the European Commission. New OBD requirements should be as consistent as possible with existing requirements to maximize reliability and to minimize system complexity, proliferation of configurations, and consumer cost. New OBD requirements from around the world are briefly reviewed and most are consistent with the original U.S. and European requirements. Worldwide OBD requirements are being further harmonized under the United Nations, Economic Commission for Europe, World Forum for Harmonization of Vehicle Regulations (WP29). Presenter David H. Ferris, General Motors Company
Technical Paper

A Study of Hybrid III 5th Percentile Female ATD Chest Accelerometers to Assess Sternum Compression Rate in Chest on Module Driver Out-of-Position Evaluations

2017-03-28
2017-01-1431
Driver out-of-position (OOP) tests were developed to evaluate the risk of inflation induced injury when the occupant is close to the airbag module during deployment. The Hybrid III 5th percentile female Anthropomorphic Test Device (ATD) measures both sternum displacement and chest acceleration through a potentiometer and accelerometers, which can be used to calculate sternum compression rate. This paper documents a study evaluating the chest accelerometers to assess punch-out loading of the chest during this test configuration. The study included ATD mechanical loading and instrumentation review. Finite element analysis was conducted using a Hybrid III - 5th percentile female ATD correlated to testing. The correlated restraint model was utilized with a Hybrid III - 50th percentile male ATD. A 50th percentile male Global Human Body Model (HBM) was then applied for enhanced anatomical review.
Technical Paper

Experimental Investigation of Fuel Film Characteristics of Ethanol Impinging Spray at Ultra-Low Temperature

2017-03-28
2017-01-0851
Increasing the injection pressure in DISI engine is an efficient way to obtain finer droplets but it will also potentially cause spray impingement on the cylinder wall and piston. Consequently, the fuel film sticking on the wall can dramatically increase the soot emission of the engine especially in a cold start condition. On the other hand, ethanol is widely used as an alternative fuel in DI engine due to its sustainable nature and high octane number. In this study, the fuel film characteristics of single-plume ethanol impinging spray was investigated. The experiments were performed under ultra-low fuel/plate temperature to simulate the cold start condition in cold areas. A low temperature thermostatic bath combined with specially designed heat exchangers were used to achieve ultra-low temperature for both the impinging plate and the fuel. Laser induced fluorescence (LIF) technique was employed to measure the thickness of fuel film deposited on the impinging plate.
Technical Paper

Virtual Car Prototyping in Realistic Driving Environment: Examples of Deep Water Crossing and Heavy Rain Management

2018-04-03
2018-01-1065
To develop future electrical and autonomous cars, it is important to virtually test the car in real driving circumstances, including on wet road or under heavy rain conditions. It is especially critical to check that no water prevents the sensors of the driving assistance systems or autonomous cars from working properly, that water intrusion does not disturb electrical equipment, and that the driver’s visibility remains good under rain condition. ESI Group has introduced the Finite Point Method (FPM) in Virtual Performance Solution (VPS) as a CFD mesh free module in order to simulate the interaction of water with the car structure. It was initially specialized for tank sloshing and water drain applications for car closures and is now extended to other application fields. The objective is to enable a holistic prediction of the car behavior under realistic driving conditions, using a virtual car prototype.
Technical Paper

Incorporating the FMVSS 201U Laboratory Experience in Simulation Using IHIT

2010-04-12
2010-01-1018
FMVSS 201U, interior head impact performance is required for each new vehicle program. In the laboratory, testing to this requirement includes laying out the target locations, defining additional robustness target points based on targeting variation, positioning the Free Motion Headform (FMH), impacting each location with the headform and measuring HIC values. The tests may involve some conservative strategies and robustness studies to protect for the worst-case scenarios, where an impact might produce the highest HIC(d) within variations of impact conditions. In order to automate the best practices and procedures for both laboratory and CAE, a process automation environment was used to develop the Interior Head Impact Toolkit (IHIT, pronounced as i-hit). The IHIT software addresses several key testing processes and is grouped into four modules.
Technical Paper

Determining Physical Properties for Rotating Components Using a Free-Free Torsional FRF Technique

2011-05-17
2011-01-1663
This paper presents a test methodology to determine the physical properties of stiffness and damping for powertrain rotating components using a free-free torsional frequency response measurement. The test methodology utilizes free-free boundary conditions and traditional modal test techniques applied to symmetric rotating components with substantially large bounding masses of known inertia. A modal test on the rotating component is executed by mounting accelerometers on opposing tangential bosses in the same direction on each of the inertial masses and impacting one of the bosses with a modal hammer to acquire frequency response functions (FRF's). Physical properties are then extracted from the FRF's using fundamental vibration relationships for an assumed two degree of freedom system. Stiffness and damping values for a variety of hollow tube carbon fiber drive shafts and a comparable steel-aluminum shaft are reported using the methodology presented.
Technical Paper

Predicting the Acoustics of Squeak and Rattle

2011-05-17
2011-01-1585
This paper discusses the development of a computationally efficient numerical method for predicting the acoustics of rattle events upfront in the design cycle. The method combines Finite Elements, Boundary Elements and SEA and enables the loudness of a large number of rattle events to be efficiently predicted across a broad frequency range. A low frequency random vibro-acoustic model is used in conjunction with various closed form analytical expressions in order to quickly predict impact probabilities and locations. An existing method has been extended to estimate the statistics of the contact forces across a broad frequency range. Finally, broadband acoustic radiation is predicted using standard low, mid and high frequency vibro-acoustic methods and used to estimate impact loudness. The approach is discussed and a number of validation examples are presented.
Technical Paper

Effects of Fretting Corrosion on Lift Glass

2011-04-12
2011-01-1434
The electrical architecture design of a rear back glass defrost grid system encompasses many critical criteria that must be integrated into the design. For example, the defrost clip location and interface to the glass must meet all vehicle performance requirements. If the defrost clip to the glass interface is not resistant to vibration and relative movement, detachment and loss of function can occur. This paper describes a back glass defrost clip with a solder joint that is robust to manufacturing variations and customer usage conditions. A designed experiment using Design for Six Sigma methodologies was performed to understand the effects of the attachment interface to the electrical wiring pigtail, and parameters that affect performance. The working constraints, testing set up, validation, and root cause investigation of the clip detachment phenomenon is covered in this paper.
Technical Paper

Gen2 GF6 Transmission Hardware and Controls Updates

2011-04-12
2011-01-1428
In an effort to increase fuel economy and improve shift quality - the GF6 family of General Motors transmissions has been analyzed for potential enhancements. The focus of this analysis was to improve fuel economy, while increasing downshift responsiveness, and manual mode sport delays. This paper describes a variety of the hardware philosophy changes, and control methods which have contributed to the next generation of GM clutch-to-clutch 6-speed transmissions. These changes to hardware and controls have led to a composite fuel economy improvement of 4.5% with no changes to shift or torque-converter scheduling. In addition, the downshift responsiveness has been significantly improved to reduce delay times by approximately 50% while virtually eliminating the dependency on engine torque reductions - ultimately allowing for stacked downshifts to progress with minimal, if any, time between shifts. Additionally, “tap shift” delays have been significantly decreased to levels near 150 ms.
Technical Paper

Development of Sensor Attachment Criteria (Immunity) - Side Impact Sensor Mounted on Door Impact Beam

2011-04-12
2011-01-1445
The sensor mounted on the door impact beam plays a major role in side impact events. The accelerations of side impact sensors are processed by sensing algorithms to make a decision on the air bag deployment. The sensing signal criterion for the deployable condition is a well understood process. However, the non-deployment sensing signal for the immunity to abuse conditions is a function of sensor attachment stiffness to the base structure. The base structure can be a door inner panel or door impact beam. In one of the production program, the acceleration based sensor attached to the impact beam showed immunity issues in the abusive door slams/opening to objects. Hence, the computer Aided Engineering (CAE) analysis was used to develop the sensor attachment criterion.
Technical Paper

Knock Detection and Estimation Based on Heat Release Strategies

2011-04-12
2011-01-1409
Engine knock has been studied extensively over the years. Its undesired effects on drivability, its potential to damage an engine, and its impact on limiting the compression ratio are the main reasons why it remains a current topic of research. This paper focuses on exploiting the connection between auto-ignition and knock. A new method based on the frequency analysis of the heat release traces is proposed to detect and estimate auto-ignition/knock robustly. Filtering the heat release signal with the appropriate bandwidth is crucial to avoid misdetection. The filter settings used in this paper are found using spectral analysis of the heat release signal. By using the proposed method, it is possible to detect auto-ignition/knock even under the presence of undesired sensor resonance effects and noise from mechanical and electrical sources.
Technical Paper

Approach to Validation Plan Development for Advanced Battery Systems in Vehicle Applications

2011-04-12
2011-01-1366
As advanced battery systems become a standard choice for mainstream production vehicle portfolios, comprehensive battery system validation plans are essential to ensure that the battery performance, reliability, and durability targets are met prior to vehicle integration. (Note: Safety and Abuse testing are outside of the scope of this paper.) The validation plan for the Chevrolet Volt Rechargeable_Energy Storage System (RESS), the first lithium-ion battery pack designed and manufactured by General Motors (GM), was developed using a functional silo approach based on the battery design requirements documentation. While the Chevrolet Volt was the lead program at General Motors to use this validation plan development approach, other GM programs with different battery system mounting locations and cooling techniques are now using this method.
Technical Paper

Thermal Behavior Study on HEV Air-Cooled Battery Pack

2011-04-12
2011-01-1368
Recently, an increased emphasis has been seen for improving the cooling uniformity and efficiency of HEV battery pack in an effort to increase the battery performance and life. This study examined the effects of geometry changes in cooling systems of battery packs on thermal behavior of battery cells and pressure drop across the battery pack. Initially, a multi-physics battery thermal model was correlated to physical test data. An analytical design of experiments (DOE) approach using Latin-hypercube technique was then developed by integrating the correlated battery thermal model with a commercial optimization code, iSIGHT, and a morphing code, DEP Morpher. The design concepts of battery pack cooling systems were finally identified by performing analytical DOE/optimization studies to estimate the effects of cooling flow and geometries of cooling ducts on the battery temperature variation and pressure drop across the battery pack.
Technical Paper

Voltec Battery Design and Manufacturing

2011-04-12
2011-01-1360
In July 2007, GM announced that it would produce the Chevy Volt, the first high-production volume electric vehicle with extended range capability, by 2010. In January 2009, General Motors announced that the Chevrolet Volt's lithium ion Battery Pack, capable of propelling the Chevy Volt on battery-supplied electric power for up to 40 miles, would be designed and assembled in-house. The T-shaped battery, a subset of the Voltec propulsion system, comprises 288 cells, weighs 190 kg, and is capable of supplying over 16 kWh of energy. Many technical challenges presented themselves to the team, including the liquid thermal management of the battery, the fast battery pack development timeline, and validation of an unproven high-speed assembly process. This paper will first present a general overview of the approach General Motors utilized to bring the various engineering organizations together to design, develop, and manufacture the Volt battery.
Technical Paper

Advanced Field Study of Rollover Sensor Equipped Vehicles

2011-04-12
2011-01-1113
General Motors (GM), OnStar and the University of Michigan International Center for Automotive Medicine (ICAM) have formed a partnership to investigate and analyze real world rollover crashes involving GM vehicles equipped with rollover sensing technology and rollover-capable roof rail airbag systems. Candidates for the study are initially identified by OnStar, who receive notification of a rollover crash through the vehicle's Automatic Crash Response system. If the customer agrees to participate in the study, medical, vehicle and crash scene information are quickly gathered. This information is then reviewed by the medical and GM engineering communities to provide field relevant learning on injury mechanisms and vehicle system performance in rollover events. This paper provides a detailed review of the field case studies collected to date.
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