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Viewing 151 to 180 of 206
2016-04-05
Technical Paper
2016-01-0035
Amey Zare, Advaita Datar, R Venkatesh, Miwako Hasegawa
Finite State Machines (FSM) commonly act as a foundation in the design of modern day embedded systems. However, FSMs are also used at various stages of software development, from the initial overall concept to the lowest level coding phase. Often, the implementation of these FSMs includes non-deterministic communication with other FSMs and the environment of the underlying system. Inappropriate handling of such communications across multiple FSMs may lead to unexpected behavior of the underlying system during execution. Detecting root cause of such unexpected behavior, is hard and time consuming. In this paper we present an automated technique for detecting and reviewing communicating FSMs. We propose a two-step approach which consists of: a) identification of all possible communicating FSMs in the code, and b) impact of external entities (events, timers etc.) on the state transitions of the identified communicating FSMs.
2016-04-05
Technical Paper
2016-01-0473
Muthukumar Arunachalam, Arunkumar S, PraveenKumar Sampath, Abdul Haiyum, Beverly Katz
Current generation passenger vehicles are built with several electronic sensors and modules which are required for functioning of passive safety systems precisely and thus directly related to overall vehicle level performance. Most of these sensors and modules are needed to be mounted on vehicle body at locations like pillar or even directly on panels based on its safety functionality and packaging requirements. The body panel or pillar poses local structural resonances and its dynamic behavior might directly affect the functioning of these sensors and modules. Hence the sufficient inertance performance level at sensor mounting locations is required for the proper functioning of those sensors and modules to meet the vibrational target requirement. Drive point modal frequency response function (FRF) analysis at full vehicle model for the frequency range up to 1000 Hz is performed using finite element method (FEM) and verified against the target level.
2016-04-05
Technical Paper
2016-01-1363
Nobuhiro Ide, Jun Hioki, Hiroki Okada
Because of its convenience high equipment ratio of electronic key system can be seen across all car makers. Ensuring performance of low frequency and ultra high frequency electromagnetic wave is a core technique in this system. Among the most important for this system is ensuring communication in the required area, and the tuning process has been a key factor in the development phase. Many man-hours and cost have been used in the past for this tuning process which was a cut-and-try based on technical experience for the convenience of the required specification in low frequency band. We have succeeded in trimming down the development process by applying our low frequency electromagnetic simulation technique described in this paper.
2016-04-05
Technical Paper
2016-01-1510
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Pratapnaidu vallabhaneni, Munenori shinada, Kazuto Sato
Active hood system helps in increasing the space between the hood inner and the engine compartment by pushing the hood upwards during a pedestrian impact. Such systems should detect all the pedestrian impacts ranging from 6YO-child to 95th%-male. To carry out rational sensor evaluation tests, a pedestrian detection impactor (PDI-2) was developed to represent the hard to detect pedestrian. To shorten the time of total experimental verification cycle and to increase the efficiency of the sensor simulation logic, a PDI-2 FE model was developed as accurately as possible to match the physical entities such as CG, weight and inertia properties. It is then evaluated with two standard pendulum tests; the results have good correlation with the physical tests. Vehicles with different sensor configurations were impacted with PDI-2 and pedestrian human models of different size & postures.
2016-04-05
Technical Paper
2016-01-0100
Sushant Kishor Hingane
The high-end vehicles with latest technology and autonomous driving experience have to bear the cost of increasing number of sensors on-board. It would prove to be the most beneficial to reduce some of the sensors in vehicle and make use of other available resources, retaining the same functionality. This paper discusses a technique of estimating the weight of seat occupant from an already existing DC motor; without using additional pressure sensors. Passenger weight information is important for seat-belt reminder system as well as supplementary restrain system that will decide the air-bag deployment. A mathematical model for a series-type DC motor is developed and simulated using MATLAB. Further, results are shared of the lab experiment performed on a lower capacity motor and verified with the simulation results. Along with the comparison of the simulated data and sensor set-up results, a concluding linear relation is formulated.
2016-04-05
Technical Paper
2016-01-1113
Thorsten Arndt, Alex Tarasow, Christian Bohn, Guido Wachsmuth, Roland Serway
Higher demands on comfort and efficiency require a continuous improvement of the shift progress. During the launch and shift progress the clutch control is used to get a smooth and efficient behavior. In this short time of acting the shifting behavior can be rated. Many control concepts use a clutch characteristic to calculate the actuator signal based on the clutch torque. Therefore, a high quality of this characteristic is necessary. Because of the dynamic process during clutch engagement the clutch characteristic needs further information to reach a high accuracy for the control algorithm. In this paper an existing clutch torque characteristic is extended to a characteristic map where the clutch torque becomes a function of the current pressure in the clutch and the clutch slip. The extension of the torque characteristic describes the slip based dependencies, e.g. the friction coefficient.
2016-04-05
Technical Paper
2016-01-0044
Sung Yul Chu, Sung Eun Jo, Kyoungbok Lee, Kwang Chul Oh, Jong Rim Lee
On-board diagnostics (OBD) of diesel vehicle requires various sensors to detect malfunctions of the systems. The PM (Particulate Matter) sensor is one of the apparatus for OBD which gather information which would be a critical factor for determining a crack of diesel particulate filters (DPFs). The main function of the PM sensor is to detect PM which penetrates cracked DPFs and convert the amount of PM to electrical values. PM sensor control unit (SCU) receives those analog signals and converts them to digital value through hardware and software solutions. A capacitive sensing method would be a stable solution because it is based on detecting not raw analog signals but electrical charges or a time constant going through the capacitive load. Therefore, it would be converted reasonable value of capacitance even the amount of raw PM is significantly low.
2016-04-05
Technical Paper
2016-01-0028
Ali Shahrokni, Peter Gergely, Jan Söderberg, Patrizio Pelliccione
In novel areas, such as Active Safety, new technologies, designs and methods are introduced at a rapid pace. To keep up with the new demands, and also requirements on Functional Safety imposed by ISO 26262, the support for the engineering methods, including tools and data management, needs to evolve as well. Generic and file-based data management tools like spreadsheet tools are popular in the industry due to their flexibility and legacy in the industry but provide poor control and traceability. At the other side of the spectrum, rigid and special-purpose tools provide structure and control of data but with limited ability to adapt to changes. As organizations become more agile, the need for flexible and agile data management increases; as products become more complex and developed in larger and more distributed teams, the need for more unified, controlled, consistent, and coherent data increases.
2016-04-05
Technical Paper
2016-01-0641
Thomas De Cuyper, Sam Bracke, Jolien Lavens, Stijn Broekaert, Kam Chana, Michel De Paepe, Sebastian Verhelst
To optimize internal combustion engines (ICEs), a good understanding of engine operation is essential. The heat transfer from the working gases to the combustion chamber walls plays an important role, not only in the performance, but also in the emissions of the engine. Besides, thermal management of ICEs is becoming more and more important as an additional tool for optimizing efficiency and emission aftertreatment. In contrast little is known about the convective heat transfer inside the combustion chamber due to the complexity of the working processes. Heat transfer measurements inside the combustion chamber pose a challenge in instrumentation due to the harsh environment. Additionally, the heat loss in a spark ignition (SI) engine shows a high temporal and spatial variation. In this paper we examine the heat transfer in a production SI ICE through the use of Thin Film Gauge (TFG) heat flux sensors. An inlet valve has been equipped with 7 TFG sensors in a row.
2016-04-05
Technical Paper
2016-01-1115
Thomas Huth, Stefan Pischinger
The demand for lower CO2 emissions requires more than an optimization of every single component but the complete system. Therefore not only the transmission has to be optimized but also the interaction of powertrain components. For the widely spread automatic transmission the main losses are caused by the actuation system, which can be reduced with an on-demand actuation system. In this paper a new on-demand electro-mechanical actuation with validation results on a clutch test bench is presented. The electro-mechanical actuator shows simulation an increase of the efficiency by 4.1 % compared to the conventional hydraulic actuation in the NEDC (New European Driving Cycle). This increase is based on the powerless end positions of the actuator (engaged and disengaged clutch). The thermal tension and wear are compensated with a disk spring. This allows a stable control over service life.
2016-04-05
Technical Paper
2016-01-0074
Michael Jensen
Electronics now control or drive a large part of automotive system design and development, from audio system enhancements to improvements in engine and drive-train performance, and innovations in passenger safety. Industry estimates suggest that electronic systems account for more than 30% of the cost of a new automobile and represent approximately 90% of the innovations in automotive design. As electronic content increases, so does the possibility of electronic system failure and the potential for compromised vehicle safety. Even when designed properly, electronics can be the weakest link in automotive system performance due to variations in component reliability and environmental conditions. Engineers need to understand worst-case system performance as early in the design process as possible.
2016-04-05
Technical Paper
2016-01-1170
George Dixon, Thomas Steffen, Richard Stobart
The TC48 project is developing a beyond state-of-the-art, exceptionally low cost, 48V Plug-in hybrid electric (PHEV) demonstration drivetrain suitable for electrically powered urban driving, hybrid operation, and internal combustion engine powered high speed motoring. This paper explains the motivation for the project, and presents the layout options considered and the rationale by which these were reduced. The vehicle simulation model used to evaluate the layout options is described and discussed. The design of the vehicle's control systems is discussed, presenting simulation results. The paper describes analysis of small vehicles in the marketplace, including aspects of range and cost, leading to the justification for the specification of the TC48 system. The design aspects of the TC48 powertrain system are discussed, particularly the sizing of the motor and battery pack.
2016-04-05
Technical Paper
2016-01-0159
Luting Wang, Chong Cao, Bo Chen
This paper studies the bi-directional power flow control between Plug-in Electric Vehicles (PEVs) and an electrical grid. A grid-tied charging system that enables both Grid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G) charging/discharging is modeled using SimPowerSystems in Matlab/Simulink environment. A bi-directional AC-DC converter and a bi-directional DC-DC buck-boost converter are integrated to charge and discharge PEV batteries. For AC-DC converter control, Predictive Current Control (PCC) strategy is employed to enable grid current to reach a reference current after one modulation period. In addition, Phase Lock Loop (PLL) and a band-stop filter are designed to lock the grid voltage phase and reduce harmonics. Bi-directional power flow is realized by controlling the mode of the DC-DC converter. Simulation tests are conducted to evaluate the performance of this bi-directional charging system.
2016-04-05
Technical Paper
2016-01-0098
Malavika Menon, Sunil Kakaye, Sudharsan Sundaram
The world today is moving more towards convenience and luxury. Auto manufacturers are being constantly challenged to provide innovative additions to a conventional vehicle in terms of attractive features. This paper describes one such invention proposed to add convenience and novelty to the use of two wheelers. The proposed system is called a “Keyless Scooter”. Derived from the idea of keyless entry in four wheelers, this system aims at extending this luxury to a larger band of population in India, i.e. users of two wheeled vehicles. The system eliminates the use of a mechanical lock and key arrangement. All functions carried out by the mechanical arrangement of lock and key are replaced with equivalent electronic systems. A “keyless scooter” is one in which a user can approach it with a key fob in his/her pocket or bag and unlock the handlebar, start the vehicle, open the luggage box, etc. without having to insert a key physically into a lock body.
2016-04-05
Technical Paper
2016-01-0155
Jaroslav Pekar, Ondrej Santin, Jaroslav Beran, Anthony D'Amato, Engin Ozatay, John Michelini, Steven Szwabowski, Dimitar Filev
Automotive cruise control systems are used to automatically maintain the speed of a vehicle at a desired speed set-point. It has been shown that fuel economy while in cruise control can be improved using advanced control methods. The objective of this paper is to validate Adaptive Nonlinear Model Predictive Controller (ANLMPC) implemented in a vehicle equipped with standard production Powertrain Control Module (PCM). Application and analysis of Model Predictive Control utilizing road grade preview information has been reported by many authors, namely for commercial vehicles. Many authors reported application (or simulation only without in-vehicle validation) of linear or nonlinear MPC based on models with fixed parameters, which may lead to inaccurate results in the real world driving conditions. The significant noise factors are namely vehicle mass, actual weather conditions, fuel type, etc.
2016-04-05
Technical Paper
2016-01-1574
Matthew Schwall, Anmol Garg, Jason Shiverick, Matthew Conley
This paper presents findings based on the examination of time-series tire pressure data. Tire pressure is important to vehicle safety due to its effects on vehicle handling and stability, as well as the effects that inappropriate tire pressure has on tread wear and tire and wheel damage. Previous research, such as NHTSA’s Tire Pressure Special Study in 2001, sampled vehicle populations and recorded tire pressures at a single point in time. Such studies yield important insights into tire pressures on individual vehicles and across the vehicle populations, but cannot provide insights into the behavior of tire pressures over time. The data presented in this paper was measured using the Tire Pressure Monitoring System (TPMS) included on all Tesla Model S vehicles. Using Tesla’s unique on-board data logging and remote data retrieval capabilities, the time history of each vehicle’s tire pressures was recorded and fleet-wide data was analyzed.
2016-04-05
Technical Paper
2016-01-0018
Rupesh Sonu Kakade, Sushovan Basu
Use of fixed-point arithmetic in the software is known to require less memory and throughput of the electronic control module. Yet the application of fixed-point software in industrial systems is limited. Developments in the microcontroller and the memory technologies can be one reason for the use of floating-point arithmetic over fixed-point arithmetic in the software. The other difficulties commonly known include iterative simulations of the software to make sure the required numerical acuracy is obtained and the associated laborious and time consuming software development. An input-tracing algorithm is presented which traces the source of data to the selected arithmetic operation in the software. Input paths are then traced back to the selected arithmetic operator from the source of data. While tracing back the method performs interval arithmetic on the source data based on the arithmetic operations encountered in the traced paths.
2016-04-05
Technical Paper
2016-01-0152
Pierre Michel, Dominik Karbowski, Aymeric Rousseau
Connectivity and automation are increasingly being developed for cars and trucks, aiming to provide better safety and better driving experience. As these technology mature and reach higher adoption rates, they will also have an impact on the energy consumption: connected and automated vehicles (CAVs) may drive more smoothly, stop less and move at faster speeds, thanks to overall improvements to traffic flows. These potential impacts are not well studied and their study tend to focus solely on conventional engine-powered cars, leaving on the side electrified vehicles such as hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs). This work intends to address this issue by analyzing the energy impact of various CAV scenarios on different types of electric vehicles using high-fidelity models. The vehicles, all midsize, one HEV, one BEV and a conventional are modeled in Autonomie, a high-fidelity forward-looking vehicle simulation tool.
2016-04-05
Technical Paper
2016-01-1409
J. Christopher Watson, Gennady Dumnov, Alexander Muslaev, Andrey Ivanov, Svetlana Shtilkind
Condensation occurrence in automotive headlights can be detrimental to consumer acceptance of a product. This paper describes a technique for transient numerical simulation of liquid film formation on surfaces during lighting thermal analysis performed using Computational Fluid Dynamics (CFD), including how the film’s properties influence the thermal solution. The numerical technique presented accounts for the change in the film thermal state and thickness due to heat exchange with external fluid flow and solid bodies, surface evaporation/condensation, melting/crystallization within the film volume, and its motion due to gravity and friction forces from the surrounding airflow.
2016-04-05
Technical Paper
2016-01-0170
Vidya Nariyambut Murali, Ashley Micks
Camera data generated in a 3D virtual environment has been used to train object detection and identification algorithms. 40 common US road traffic signs were used as the objects of interest during the investigation of these methods. Traffic signs were placed randomly alongside the road in front of a camera in a virtual driving environment, after the camera itself was randomly placed along the road at an appropriate height for a camera located on a vehicle’s rear view mirror. In order to best represent the real world, effects such as shadows, occlusions, washout/fade, skew, rotations, reflections, fog, rain, snow and varied illumination were randomly included in the generated data. Images were generated at a rate of approximately one thousand per minute, and the image data was automatically annotated with the true location of each sign within each image, to facilitate supervised learning as well as testing of the trained algorithms.
2016-04-05
Technical Paper
2016-01-0066
Joe Hupcey, Bryan Ramirez
The #1 priority in vehicle security is to harden the “root of trust”; from which everything else – the hardware, firmware, OS, and application layer’s security – is derived. If the root of trust can be compromised, then the whole system is vulnerable. In the near future the root of trust will effectively be an encryption key – a digital signature for each vehicle — that will be stored in a secure memory element inside all vehicles. In this paper we will show how a mathematical, “formal” analysis techniques can be applied to ensure that this secure storage can’t be (A) read by an unauthorized party or accidentally “leak” to the outputs; or (B) be altered, overwritten, or erased by unauthorized entities. We will include a real world case study from a consumer electronics maker that has successfully used this technology secure their products from attacks 24/7/365.
2016-04-05
Technical Paper
2016-01-0129
Ashlie B. Hocking, M. Anthony Aiello, John C. Knight, Shinichi Shiraishi, Masahiro Yamaura, Nikos Arechiga
For many crucial applications, establishing important properties of Simulink models by testing is either extremely resource intensive or impossible, and proof of the properties is highly desirable. Many Simulink models rely upon discrete-valued functions for which the function values are defined as a lookup table of correspondences between values in the domain and range. Such tables arise in applications for which no known closed-form algebraic definition exists. For example, a discrete-valued function might be defined for the physical performance of a device such as a servomotor where the values of the function are determined by laboratory measurement. In general, the proof of a property for a model that includes a discrete-valued function has to be by case analysis. For a single function and with mechanical support, case analysis is manageable.
2016-04-05
Technical Paper
2016-01-0138
Bernard Dion
This paper presents an approach for the development of ISO 26262 compliant software applications based on Model-Based Design (MBD) and certified Automatic Code Generation (ACG). When using such a method, strong benefits can be achieved in reducing software verification costs while meeting the objectives of ISO 26262 at the highest ASIL levels. After a brief summary of the ISO 26262 standard, the paper presents a detailed analysis of what is really expected by the standard for tool qualification, with strong emphasis on having a Safety Case that takes into accounts the various stakeholders, i.e. the tool developer and the tool user, considering all possible failure conditions and mitigation actions by performing hazard analysis and risk assessment (e.g. HAZOP). A Safety Case is then built for the qualification of the Automatic Code Generator (ACG) and it shows the various mitigation actions that should be taken.
2016-04-05
Technical Paper
2016-01-0139
Andreas Himmler, Klaus Lamberg, Tino Schulze, Jann-Eve Stavesand
Developers of safety-critical systems need to verify the output of software tools in order to ensure their suitability for safety-relevant applications. The importance of verification holds specifically for test automation tools that are used to run hardware-in-the-loop (HIL) tests of safety-related software automatically 24/7. This paper will focus on two aspects that maximize the productivity of a COTS test automation tool: (a) Minimize the efforts for tool users for tool certification and (b) maximize the productivity for tool application. The latter refers to a new concept of signal-based test description. It is common sense that a test automation tool that automatically performs tests 24/7 has a tool confidence level of TCL 3. This causes a major initial hurdle for tool users, since the resulting required tool qualification is time-consuming and requires advanced knowledge.
2016-04-05
Technical Paper
2016-01-1458
Ryuta Ono, Wataru Ike, Yuki Fukaya
We have developed for packaged safety system called Toyota Safety Sense P to deal with various type of accident based on accident analysis. Based on accident analysis, we developed five functions which are Pre-collision system (PCS) to deal with rear-end collision, pedestrian PCS to deal with pedestrian accident included under crossing, Lane Departure Alert(LDA) to assist deviating accident on a road, Automatic high beam(AHB) to assist ensuring the forward visibility, Adaptive Cruise Control(ACC) to reduce drivers operating load. “Toyota Safety Sense P” has been developed and formed as one package. These functions have been equipped optionally so far, however we aim TSS P to spread extensively by packaging five functions with a set. It is very important a technology to detect a danger of accident in this safety system.
2016-04-05
Technical Paper
2016-01-0130
Satoshi Otsuka, Kohei Sakurai
Highly-automated driving systems have a responsibility to keep the vehicle safety even in abnormal conditions such as random or systematic failures. However, creating redundancy of systems to correspond failures increases the system cost, and simple redundancy cannot detect systematic failures because the failures occur in each system at the same time. Systematic failures in automated driving systems can be verified insufficiently in a development phase due to numerous patterns of input parameters from outside of the system. In this research, we constructed a safety concept with safety sustainer for highly-automated driving system. The safety sustainer is designed for keeping the vehicle safety for several seconds in a failure mode, and notifying driver that the system in a failure mode to take over the control.
2016-04-05
Technical Paper
2016-01-0822
Due to the direct injection of fuel into combustion chamber, particulate emission became a serious problem in DISI engine. Especially, significant amount of particulate emission is produced at cold start condition. In this research, the main interest was the particulate emission characteristics under catalyst heating condition, since it is one of the significant particulate-emission-producing stage under cold start condition. A single-cylinder optically accessible engine was used to investigate the effect of injection strategies on particulate emission characteristics under catalyst heating condition. Split injection strategy during intake stroke was applied with various injection pressure and injection timing. By using luminosity analysis of diffusion flame during the combustion phase, PM formation characteristics of each injection strategies were studied. In addition, factors that affect PM formation were analyzed by fuel injection visualization.
2016-04-05
Technical Paper
2016-01-1425
Thomas McWilliams, Daniel Brown, Bryan Reimer, Bruce Mehler, Jonathan Dobres
Changes in physiological and operational behavior following lane departure warnings are explored in current production automotive systems. Different implementations employing auditory and haptic lane departure warning alerts were recorded in highway driving conditions from the factory installed lane departure warning systems. The lane departure warning events took place during single task driving periods as well as dual task driving. Dual task periods consisted of the driver interacting with the vehicle’s production interface to perform a secondary visual-manual (e.g., radio tuning, contact dialing, etc.) or auditory-vocal (e.g. destination address entry, contact dialing, etc.) tasks. Driver physiology and behavior were recorded and analyzed for pre-event and post-event conditions. To normalize between vehicles, percentage changes between pre-event and post-event measures were calculated.
2016-04-05
Technical Paper
2016-01-0127
Agish George, William Taylor, Jody Nelson
One of the key premises of the ISO 26262 functional safety standard is the development of an appropriate Technical Safety Concept for the item under development. This is specified in detail in Part 4 of the standard – Product development at the system level. The Technical safety requirements and the technical safety concept form the basis for deriving the hardware and software safety requirements that are then used by engineering teams for developing a safe product. Just like any other form of product development, making multiple revisions of the requirements are highly undesirable. This is primarily due to cost increases, chances of having inconsistencies within work products and its impact on the overall project schedule. Good technical safety requirements are in fact the foundation for an effective functional safety implementation.
2016-04-05
Technical Paper
2016-01-1228
Faizul Momen, Khwaja M. Rahman, Yochan Son, Peter Savagian
A permanent magnet AC (PMAC) motor is used to design the propulsion system of Chevrolet Bolt battery electric vehicle (BEV). Magnets are buried inside the rotor in two layer ‘V’ arrangement. The double layer magnet arrangement improves rotor saliency resulting in improved motor performance. The double layer arrangement also provides flexibility in the rotor design to lower torque ripple and stator teeth radial force, the major drivers for airborne acoustic noise and vibration. The Chevrolet Bolt electric machine rotor design additionally optimizes the magnet placement between the adjacent poles asymmetrically to further lower torque ripple and radial force. Similar to Gen1 Chevrolet Spark BEV electric motor, a pair of small slot is stamped in each rotor pole near the rotor outer surface to lower torque ripple and radial force.
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