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Viewing 1 to 30 of 216
2015-04-14
Technical Paper
2015-01-1482
Bisheshwar Haorongbam, Anindya Deb, Clifford Chou
Hat-sections, single and double, made of steel are frequently encountered in automotive body structural components. These components play a significant role in terms of impact energy absorption during vehicle crashes thereby protecting occupants of vehicles from severe injury. However, with the need for higher fuel economy and for compliance to stringent emission norms, auto manufacturers are looking for means to continually reduce vehicle body weight either by employing lighter materials like aluminum and fiber-reinforced plastics, or by using higher strength steel with reduced gages, or by combinations of these approaches. Unlike steel hat-sections which have been extensively reported in published literature, the axial crushing behavior of hat-sections made of fiber-reinforced composites may not have been adequately probed.
2015-04-14
Technical Paper
2015-01-1483
Anindya Deb, N Shivakumar, Clifford Chou
Rigid polyurethane (PU) foam finds wide applications as a lightweight material in impact safety design such as improving occupant safety in vehicle crashes. The two principal reacting compounds for formulating such a foam are variants of polyol and isocyanate. In the present study, an alternative mechanical engineering-based approach for determining, with confidence, the desirable ratio of reacting compounds for formulation of a rigid/crushable PU foam for mechanical applications is demonstrated. According to the present approach, PU foam samples are prepared by varying the mixing ratio over a wide range. The desirable mixing ratio is shown to be the one that optimizes key mechanical properties under compression such as total absorbed energy, specific absorbed energy and energy absorption efficiency.
2015-04-14
Technical Paper
2015-01-0496
Anindya Deb, Ranga Srinivas Gunti, Clifford Chou, Utpal Dutta
The present work is concerned with the objective of multi disciplinary optimization (MDO) of an automotive front end structure using truncated finite element model. A truncated finite element model of a real world vehicle is developed and its efficacy for use in design optimization is demonstrated. The main goal adopted here is minimizing the weight of the front end structure meeting NVH, durability and crash safety targets. Using the Response Surface Method (RSM) and the Design Of Experiments (DOE) technique, second order polynomial response surfaces are generated for prediction of the structural performance parameters such as lowest modal frequency, fatigue life, and peak deceleration value.
2015-04-14
Technical Paper
2015-01-1384
Richard Young, Jing Zhang
In this age of the Internet of Things, people expect in-vehicle interfaces to work just like a smartphone. Our understanding of the reality of in-vehicle interfaces is quite contrary to that. We review the fundamental principles and metrics for automotive visual-manual driver distraction guidelines. We note the rise in portable device usage in vehicles, and debunk the myth of increased crash risk when conversing on a wireless device. We advocate that portable electronic device makers such as Apple and Google should adopt driver distraction guidelines for application developers (whether for tethered or untethered device use in the vehicle). We present two design implications relevant to safe driving. First, the Rule of Platform Appropriateness: design with basic principles of ergonomics, and with driver’s limited visual, manual and cognitive capacity, in mind. Second, the Rule of Simplicity: thoughtful reduction in the complexity of in-vehicle interfaces.
2015-04-14
Technical Paper
2015-01-1235
Kevin L. Snyder, Jerry Ku
The Wayne State University (WSU) EcoCAR2 student team converted a 2013 Chevrolet Malibu into a plug-in parallel hybrid for their participation in the EcoCAR2 design competition. EcoCAR2 was a three-year Department of Energy (DoE) Advanced Vehicle Technical Competition (AVTC) for 15 select university student teams competing on designing, building, and then optimizing their different plug-in hybrid reengineering of GM donated vehicles. WSU’s Parallel Through The Road (PTTR) powertrain design provides 49 km (30 miles) of electric driving using a rear axle mounted traction motor before the front axle mounted ethanol (E85) Internal Combustion Engine (ICE) powertrain is needed. This design allows the vehicle to operate the traction motor and ICE independently for increased reliability and also together: for increased fuel economy or increased dynamic performance.
2015-04-14
Technical Paper
2015-01-1658
Xi Luo, Xin Yu, Marcis Jansons
As engine efficiencies continue to rise, heat transfer losses increase in relative importance. Understanding of these phenomena requires accurate in-cylinder wall temperature measurements. A novel dual wavelength infrared diagnostic has been developed to measure in-cylinder surface temperatures with potential temporal resolutions exceeding 1ns. The diagnostic has the capability to measure low amplitude, high frequency temperature variations, such as those occurring during the gas exchange process. A dual wavelength ratio method has also been developed to correct for background scattering reflections. The assumption that scatting reflection effect is constant during an engine cycle has also been provided at all exam engine condition. In-cylinder surface temperatures have been simultaneously measured during motored engine conditions with three independent measurement techniques: thermocouple, laser-induced phosphorescence, and the dual wavelength infrared diagnostic.
2015-04-14
Technical Paper
2015-01-0906
Xin Yu, Xi Luo, Marcis Jansons, Doohyun Kim, Jason Martz, Angela Violi
A systemic experimental fuel surrogate validation approach is proposed for a compression ignition application, and applied to validate a Jet-A POSF4658 fuel surrogate. The approach examines agreement of both physical and chemical properties in a real engine environment during four sequential but distinct combustion phases. Evaporating spray measurement using Mie Scattering are applied to compare the in-cylinder spray behavior of the surrogate, its target fuel, and for reference, n-heptane. Early mixture formation and low temperature reaction behavior were investigated using 2-D broadband chemiluminescence imaging. The high temperature ignition and combustion chemistry were studied using OH chemiluminescence imaging. Engine-out UHC, NO and soot emission characteristics were compared at different intake conditions, injection pressures and injection strategies.
2015-04-14
Technical Paper
2015-01-1385
Li Hsieh, Sean Seaman, Richard Young
As advanced electronic technology continues to be integrated into in-vehicle and portable devices, it is important to understand how drivers handle multitasking in order to maintain safe driving while reducing driver distraction. The U.S. National Highway Traffic Safety Administration has made driver distraction mitigation a major initiative, proposing guidelines for visual-manual tasks in vehicle-embedded systems in 2013 [1] and announcing plans for portable and aftermarket (PAD) devices guidelines in 2014 and for voice-based task guidelines in 2015. Currently, several types of Detection Response Tasks (DRTs) for assessing selective attention in detection of visual, auditory, tactile and haptic events while driving have been under investigation by the ISO Driving Distraction working group (ISO TC22/SC13/WG8 DRT Task Force).
2015-04-14
Technical Paper
2015-01-0806
Valentin Soloiu, Spencer Harp, Channing Watson, Martin Muinos, Sherwin Davoud, Gustavo Molina, Brian Koehler, Julia Heimberger, Marcis Jansons, Christopher Butts
This study evaluates the performance of an indirect injection (IDI) diesel engine fueled with cottonseed biodiesel while assessing the IDI engine multi-fuel capability. Millions of tons of cotton seeds are available in the southeast of the USA every year and they contain oils that can be transesterified. An investigation of combustion, emissions, and efficiency was performed in this study, using mass ratio blends of 20-50% cottonseed biodiesel (CS20 and CS50) in ultra-low sulfur diesel #2 (ULSD#2). Each investigation was run at 2400 rpm with loads of 4-6.3 IMEP and compared to the reference fuel ULDS#2 at respective loads. The experimental engine used in the testing was an IDI compression ignition engine with a 77mm bore and a triple vortex auxiliary combustion chamber.
2015-04-14
Technical Paper
2015-01-1232
Yuxia Liu, Idan Kovent, Miriam Di Russo, Jerry C. Ku
As the automotive control systems are becoming more complex and advanced, there are increasing demands on software automated testing to reduce the costs, resources and time associated with such testing. In this paper, an in-situ approach for automated testing is developed for EcoCAR2 project at Wayne State University (WSU). EcoCAR2 is a three-year student design competition sponsored by Department of Energy, under the Advanced Vehicle Technology Competitions (AVTC) program, to re-engineer a 2013 General Motors Chevrolet Malibu. The WSU EcoCAR2 team has developed its in-house vehicle controls code starting with a set of requirements. Code validation is conducted at each stage via software-in-the-loop (SIL), hardware-in-the-loop (HIL), and vehicle-in-the-loop (VIL) testing.
2015-04-14
Technical Paper
2015-01-1230
Ahmed Imtiaz Uddin, Jerry Ku
It is well known that thermal management is a key factor in design and performance analysis of Lithium-ion (Li-ion) battery, which is widely adopted for hybrid and electric vehicles. In this paper, an air cooled battery thermal management system design has been proposed and analyzed for mild hybrid vehicle application. Computational fluid dynamics (CFD) analysis was performed using CD-adapco’s STAR-CCM+ solver and Battery Simulation Module (BMS) application to predict the temperature distribution within a module comprised of twelve 40Ah Superior Lithium Polymer Battery (SLPB) cells connected in series. The cells are cooled by air through aluminum cooling plate sandwiched in-between every pair of cells. The cooling plate has extended the cooling surface area exposed to cooling air flow. Cell level electrical and thermal simulation results were validated against experimental measurements.
2015-04-14
Technical Paper
2015-01-1396
Xiangjie Meng, Xin Tao, Wenjun Wang, Chaofei Zhang, Bo Cheng, Bo Wang, Chengpeng Zhou, Xiaoping Jin, Chao Zeng, John Cavanaugh, Chaoyang Chen
: Low back pain has a higher prevalence among drivers who have long term history of vehicle operations. Vehicle vibration has been considered to be a causative factor associated with low back pain; however, the fundamental mechanism that relates vibration to low back pain is still not clear. It is hypothesized that vibration causes vibration in the muscles at resonant frequencies, leading to increased muscle activity and muscle fatigue during prolonged driving. The aim of this study was to determine the vibration frequency that causes the increase of muscle activity that can lead to muscle fatigue and low back pain. This study investigated the effects of various vibration frequencies on the lumbar and thoracic paraspinal muscle responses among 11 seated volunteers exposed to sinusoidal whole body vibration varying from 4Hz to 30Hz. The accelerations of the seat and the pelvis were recorded during various frequency of vibrations.
2015-04-14
Technical Paper
2015-01-1228
Zhuoran Zhang, Miriam Di Russo, Ahmed I. Uddin, Dhanya Sankaran, Jerry C. Ku
This paper presents the work performed by the Wayne State University (WSU) EcoCAR 3 student design competition team in its preparation for the hybrid electric vehicle architecture selection process. This process is recognized as one of the most pivotal steps in the EcoCAR 3 competition. With a key lesson learned from participation in EcoCAR 2 on “truly learning how to learn,” the team held additional training sessions on architecture selection tools and exercises with the goal of improving both fundamental and procedural skills. The work conducted represents a combination of the architecture feasibility study and final selection process in terms of content and procedure, respectively. At the end of this study the team was able to identify four potentially viable hybrid powertrain architectures, and thoroughly analyze the performance and packaging feasibility of various component options.
2015-04-14
Technical Paper
2015-01-1324
Guangtian Gavin Song, Chin-An Tan
In automotive industry, door slam CAE fatigue life analysis is very important in door durability evaluation and optimization to dramatically reduce the design cycle and minimize the expensive durability testing. Couple of linear stress based methodologies, such as inertia relief method, direct transient response solution, or local strain approach, have been applied in CAE. Linear material properties are used in these linear stress based methodologies. In local strain approach, contact surface could be defined in the necessary area. Then the stress time history is retrieved and input to further fatigue life analysis or firstly converted to nonlinear stress with Neuber’s rule to consider plastic deformation effect. But under some circumstances, the structure may have large local area plastic deformation. So the linear stress based methodology can’t precisely predict the load path, and further affect the accuracy of fatigue analysis.
2014-05-20
Journal Article
2014-01-9021
Y. Gene Liao, Molly O'Malley, Allen Quail
Fuel consumption reduction on medium-duty tactical truck has and continues to be a significant initiative for the U.S. Army. The Crankshaft-Integrated-Starter-Generator (C-ISG) is one of the parallel hybrid propulsions to improve the fuel economy. The C-ISG configuration is attractive because one electric machine can be used to propel the vehicle, to start the engine, and to be function as a generator. The C-ISG has been implemented in one M1083A1 5-ton tactical cargo truck. This paper presents the experimental assessments of the C-ISG hybrid truck characteristics. The experimental assessments include all electric range for on- and off-road mission cycles and fuel consumption for the high voltage battery charging. Stationary tests related to the charging profile of the battery pack and the silent watch time duration is also conducted.
2014-04-15
Journal Article
2014-01-9077
Amit Shrestha, Ziliang Zheng, Tamer Badawy, Naeim Henein, Peter Schihl
This paper presents a new approach for the development of six different JP-8 surrogates for application in diesel cycle simulation. The approach involves a step-wise formulation of 2-, 3-, and 4-component surrogates from a list of pure compounds which are selected based on several criteria. A MATLAB code is developed and is used in conjunction with the Ignition Quality Tester (IQT) and HYSYS software in order to formulate optimal surrogates. The first part of the results shows a comparison between the calculated and the measured DCNs for six surrogates. The differences in the properties such as the density, volatility, lower heating value, H/C ratio, molecular weight, and threshold sooting index of the surrogates and the JP-8 are also highlighted. This is followed by the evaluation of the surrogates with respect to the target JP-8 fuel. The evaluation is made in terms of ignition delays and the rate of heat release at three different IQT test temperatures.
2014-04-01
Technical Paper
2014-01-1434
Mark A. Shost, Ming-Chia Lai, Bizhan Befrui, Peter Spiekermann, Daniel L. Varble
Abstract Development of in-cylinder spray targeting, plume penetration and atomization of the gasoline direct-injection (GDi) multi-hole injector is a critical component of combustion developments, especially in the context of the engine downsizing and turbo-charging trend that has been adopted in order to achieve the European target CO2, US CAFE, and concomitant stringent emissions standards. Significant R&D efforts are directed towards the optimization of injector nozzle designs in order to improve spray characteristics. Development of accurate predictive models is desired to understand the impact of nozzle design parameters as well as the underlying physical fluid dynamic mechanisms resulting in the injector spray characteristics. This publication reports Large Eddy Simulation (LES) analyses of GDi single-hole skew-angled nozzles, with β=30° skew (bend) angle and different nozzle geometries.
2014-04-01
Technical Paper
2014-01-1921
Kevin L. Snyder, Jerry Ku
Abstract The Wayne State University (WSU) EcoCAR2 student team is investigating powertrain optimizations as a part of their participation in the EcoCAR2 design competition for the conversion of a 2013 Chevrolet Malibu into a plug-in hybrid. EcoCAR2 is the current three-year Department of Energy (DoE) Advanced Vehicle Technical Competition (AVTC) for 15 select university student teams competing on designing, building, and then optimizing their Plug-In Hybrid conversions of GM donated vehicles. WSU's powertrain design provides for approximately 56-64 km (35-40 miles) of electric driving before the Internal Combustion Engine (ICE) powertrain is needed. When the ICE is started, the ICE traditionally goes through a cold start with the engine, transmission, and final drive all at ambient temperature. The ICE powertrain components are most efficient when warmed up to their normal operating temperature, typically around 90-100 °C.
2014-04-01
Technical Paper
2014-01-1922
Robert Jesse Alley, Patrick Walsh, Nicole Lambiase, Brian Benoy, Kristen De La Rosa, Douglas Nelson, Shawn Midlam-Mohler, Jerry Ku, Brian Fabien
Abstract EcoCAR 2: Plugging in to the Future (EcoCAR) is North America's premier collegiate automotive engineering competition, challenging students with systems-level advanced powertrain design and integration. The three-year Advanced Vehicle Technology Competition (AVTC) series is organized by Argonne National Laboratory, headline sponsored by the U. S. Department of Energy (DOE) and General Motors (GM), and sponsored by more than 30 industry and government leaders. Fifteen university teams from across North America are challenged to reduce the environmental impact of a 2013 Chevrolet Malibu by redesigning the vehicle powertrain without compromising performance, safety, or consumer acceptability. During the three-year program, EcoCAR teams follow a real-world Vehicle Development Process (VDP) modeled after GM's own VDP. The EcoCAR 2 VDP serves as a roadmap for the engineering process of designing, building and refining advanced technology vehicles.
2014-04-01
Technical Paper
2014-01-1927
Mengjia Cao, Idan Kovent, Jerry Ku
Abstract Hybrid electric vehicle (HEV) is one of the most highly pursued technologies for improving energy efficiency while reducing harmful emissions. Thermal modeling and control play an ever increasing role with HEV design and development for achieving the objective of improving efficiency, and as a result of additional thermal loading from electric powertrain components such as electric motor, motor controller and battery pack. Furthermore, the inherent dual powertrains require the design and analysis of not only the optimal operating temperatures but also control and energy management strategies to optimize the dynamic interactions among various components. This paper presents a complete development process and simulation results for an efficient modeling approach with integrated control strategy for the thermal management of plug-in HEV in parallel-through-the road (PTTR) architecture using a flexible-fuel engine running E85 and a battery pack as the energy storage system (ESS).
2014-04-01
Technical Paper
2014-01-1914
Idan Kovent, Jerry Ku
Abstract The Wayne State University EcoCAR2 team provided its members with Modeling and Simulation training course for the second summer of the competition. EcoCAR2 is a three-year Advanced Vehicle Technology Competition (AVTC) sponsored by General Motors and the Department of Energy. The course lasted three months and included 45 hours of formal lectures and class hands-on work and an estimated one hundred and fifty hours in home assignments that directly contributed to the team's deliverables. The course described here is unique. The design and class examples were extracted from an in-house complete vehicle simulation and control code to ensure hands-on, interactive training based on real-world problems. The course investigated the physics behind every major powertrain component of a hybrid electric vehicle and the different ways to model the components into a full vehicle simulation.
2014-04-01
Journal Article
2014-01-0751
Prabath Arachchige, Mohamed Abderrahmane, Ana M. Djuric
Path planning and re-planning for serial 6 degree of freedom (DOF) robotic systems is challenging due to complex kinematic structure and application conditions which affects the robot's tool frame position, orientation and singularity avoidance. These three characteristics represent the key elements for production planning and layout design of the automated manufacturing systems. The robot trajectory represents series of connected points in 3D space. Each point is defined with its position and orientation related to the robot's base frames or predefined user frame. The robot will move from point to point using the desired motion type (linear, arc, or joint). The trajectory planning requires first to check if robot can reach the selected part(s). This can be simply done by placing the part(s) inside the robot's work envelope. The robot's work envelope represents a set of all robots' reachable points without considering their orientation.
2014-02-17
Article
The four-year, $15 million development program with UW-Madison and Wayne State University aims to achieve diesel levels of efficiency and torque, with lower emissions and cost—in an advanced gasoline-fueled engine.
2013-09-08
Technical Paper
2013-24-0010
Xin Yu, Kan Zha, Xi Luo, Dinu Taraza, Marcis Jansons
A means of validating numerical simulations has been developed which utilizes chemiluminescence measurements from an internal combustion engine. By incorporating OH*, CH2O* and CO2* chemiluminescence sub-mechanisms into a detailed n-heptane reaction mechanism, excited species concentration and chemiluminescence light emission were calculated. The modeled line-of-sight chemiluminescence emission allows a direct comparison of simulation results to experimentally measured chemiluminescence images obtained during combustion in an optically accessible compression ignition engine using neat n-heptane fuel. The spray model was calibrated using in-cylinder liquid penetration length Mie scattering measurements taken from the jets of the high-pressure piezo injector.
2013-04-08
Technical Paper
2013-01-0255
Bizhan Befrui, Andreas Aye, Peter Spiekermann, Daniel L. Varble, Mark A. Shost, Ming-Chia Lai, Jin Wang
Improvement of spray atomization and penetration characteristics of the gasoline direct-injection (GDi ) multi-hole injector is a critical component of the GDi combustion developments, especially in the context of engine down-sizing and turbo-charging trend that is adopted in order to achieve the European target CO₂, US CAFE, and concomitant stringent emissions standards. Significant R&D efforts are directed towards optimization of the nozzle designs, in order to improve the GDi multi-hole spray characteristics. This publication reports VOF-LES analyses of GDi single-hole skew-angled nozzles, with β=30° skew (bend) angle and different nozzle geometries. The objective is to extend previous works to include the effect of nozzle-hole skew angle on the nozzle flow and spray primary breakup. VOF-LES simulations of a single nozzle-hole of a purpose-designed GDi multi-hole seat geometry, with three identical nozzle-holes per 120° seat segment, are performed.
2013-04-08
Technical Paper
2013-01-1535
Dennis A. Corrigan, Xiao Liu
The central performance requirement for electrochemical energy storage systems for the full power-assist hybrid electric vehicle (HEV) is pulse power capability, typically 25-40 kW pulse power capability for 10 seconds duration. Standard test procedures utilize constant current pulses. However, in the HEV application, the power transient for acceleration is a ramped power transient and the power transient for regenerative braking power is a descending power ramp. This paper compares the usable power capability of batteries and supercapacitors under constant current, constant power, and ramped power transients. Although the usable battery discharge power is relatively insensitive to the transient type applied, 10-40% higher regenerative braking charge capability is observed with ramped power transients. With supercapacitors, the discharge and charge capability is much more strongly dependent on the type of power transient.
2013-04-08
Technical Paper
2013-01-1682
Valentin Soloiu, Henry Ochieng, Jabeous Weaver, Marvin Duggan, Spencer Harp, Brian Vlcek, Craig Jenkins, Marcis Jansons
"The Single Fuel Forward Policy" legislation enacted in the United States mandates that deployed U.S. military ground vehicles must be operable with aviation fuel (JP-8). This substitution of JP-8 for diesel raises concerns about the compatibility of this fuel with existing reciprocating piston engine systems. This study investigates the combustion, emissions, and performance characteristics of blends of JP-8 and Ultra Low Sulfur Diesel (ULSD) fuels with similar cetane numbers (CN), 48 (JP-8) and 47(ULSD), respectively, in a direct injection (DI) compression ignition engine over the load range of 3-8 bar imep at 1400 rpm. The results showed that JP-8 blends and ULSD had ignition delays ranging from approximately 1.0-1.4 ms and an average combustion duration time in the range of 47-65 CAD. Cylinder maximum heat flux values were found to be between 2.0 and 4.4 MW/m₂, with radiation flux increasing much faster than convection flux while increasing the imep.
2013-04-08
Technical Paper
2013-01-0549
Kevin L. Snyder, Jerry Ku
The Wayne State University (WSU) EcoCAR2 student team is participating in a design competition for the conversion of a 2013 Chevrolet Malibu into a plug-in hybrid. The team created a repeatable on-road test drive route using local public roads near the university that would be of similar velocity ranges contained in the EcoCAR2 4-Cycle Drive Schedule - a weighted combination of four different EPA-based drive cycles (US06 split into city and highway portions, all of the HWFET, first 505 seconds portion of UDDS). The primary purpose of the team's local on-road route was to be suitable for testing the team's added hybrid components and control strategy for minimizing petroleum consumption and tail pipe emissions. Comparison analysis of velocities was performed between seven local routes and the EcoCAR2 4-Cycle Drive Schedule. Three of the seven local routes had acceptable equivalence for velocity (R₂ ≻ 0.80) and the team selected one of them to be the on-road test drive route.
2013-04-08
Technical Paper
2013-01-0541
Kevin L. Snyder, Love Lor, Jerry Ku
The Wayne State University (WSU) EcoCAR2 student team designed, modeled, Model-In-the-Loop (MIL) tested, Software-In-the-Loop (SIL) simulation tested, and Hardware-In-the-Loop (HIL) simulation tested the team's conversion design for taking a 2013 Chevrolet Malibu and converting it into a Parallel-Through-The-Road (PTTR) plug-in hybrid. The 2013 Malibu is a conventional Front Wheel Drive (FWD) vehicle and the team's conversion design keeps the conventional FWD and adds a Rear Wheel Drive (RWD) powertrain consisting of an electric motor, a single speed reduction gearbox and a differential to drive the rear wheels -where none of these previously existed on the rear wheels. The RWD addition creates the PTTR hybrid powertrain architecture of two driven axles where the mechanical torque path connection between the two powertrains is through the road, rather than a mechanical torque path through gears, chains, or shafts.
2013-04-08
Technical Paper
2013-01-0570
Idan David Regev, Jerry Ku
Wayne State University EcoCAR2 team is designing and modifying a GM-donated Chevrolet Malibu 2013 to a Parallel-Through-The-Road (PTTR) plug-in hybrid. A Freescale-donated Center Stack Unit (CSU) touchscreen display is used for Human Machine Interface (HMI). Surveys were conducted to better understand CSU functionality expectations. One required function was increasing driving efficiency. Other hybrid and electric vehicles HMI systems present driving and environmental settings efficiencies such as average fuel economy, lifetime fuel economy, electric charge used, fuel used, distances driven on each power source, instantaneous power gauge and instantaneous driver efficiency gauge. These offer drivers a large sum of information but with no provision to analyze and improve one's driving habits unless one has the required knowledge to understand the causes behind the values presented.
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