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Technical Paper
2014-04-01
Robert Golimbioschi, Giampiero Mastinu, Luca Cordioli, Massimiliano Gobbi, Davide Tagliabue, Giorgio Previati, Francesco Braga
Abstract A new electric powertrain and axle for light/medium trucks is presented. The indoor testing and the simulation of the dynamic behavior are performed. The powertrain and axle has been produced by Streparava and tested at the Laboratory for the Safety of Transport of the Politecnico di Milano. The tests were aimed at defining the multi-physics perfomance of the powertrain and axle (efficiency, acceleration and braking, temperature and NVH). The whole system for indoor tests was composed by the powertrain and axle (electric motor, driveline, suspensions, wheels) and by the test rig (drums, driveline and electric motor). The (driving) axle was positioned on a couple of drums, and the drums provided the proper torques to the wheels to reproduce acceleration and braking. Additionally a cleat fixed on one drum excited the vibration of the suspensions and allowed assessing NVH performance. The simulations were based on a special co-simulation between 1D-AMESIM and VIRTUAL.LAB. The contact between the wheels and the drums of the test rig were simulated by means of VIRTUAL.LAB.
Technical Paper
2014-04-01
Ehsan Samadani, Siamak Farhad, Satyam Panchal, Roydon Fraser, Michael Fowler
Abstract In this paper, initial results of Li-ion battery performance characterization through field tests are presented. A fully electrified Ford Escape that is equipped by three Li-ion battery packs (LiFeMnPO4) including an overall 20 modules in series is employed. The vehicle is in daily operation and data of driving including the powertrain and drive cycles as well as the charging data are being transferred through CAN bus to a data logger installed in the vehicle. A model of the vehicle is developed in the Powertrain System Analysis Toolkit (PSAT) software based on the available technical specification of the vehicle components. In this model, a simple resistive element in series with a voltage source represents the battery. Battery open circuit voltage (OCV) and internal resistance in charge and discharge mode are estimated as a function of the state of charge (SOC) from the collected test data. It is shown that although the OCV should be measured under no-load condition, still it can be estimated with an acceptable accuracy (∼5%) from the driving data.
Technical Paper
2014-04-01
Jakub Zebala, Wojciech Wach
Abstract The objective of the paper is to present the results of an investigation of the effect of reduced tire pressure on car lateral dynamics in lane change maneuver. The intended aim was attained by performing bench and road tests. The aim of the bench tests was parameterization of the mathematical model of the tested car. The road tests covered the vehicle motion with reduced and no tire pressure on a curvilinear track adequate for bypassing an unexpected appearing obstacle. Next, simulations in PC-Crash were performed, and the results were compared with those obtained in experiments.
Technical Paper
2014-04-01
Bryan Randles, Daniel Voss, Isaac Ikram, Christopher Furbish, Judson Welcher, Thomas Szabo
Determination of vehicle speed at the time of impact is frequently an important factor in accident reconstruction. In many cases some evidence may indicate that the brake pedal of a striking vehicle was disengaged, and the vehicle was permitted to idle forward prior to impacting the target vehicle. This study was undertaken to analyze the kinematic response of various vehicles equipped with automatic transmissions while idling, with the transmissions in drive and the brake pedals disengaged. An array of sedans, SUV's and pickup trucks were tested under 3 roadway conditions (flat, medium slope and high slope). The vehicle responses are reported and mathematical relationships were developed to model the idle velocity profiles for flat and sloped roadway surfaces.
Standard
2013-07-24
This SAE Recommended Practice establishes a uniform procedure for testing the brake systems (service and parking) of all passenger cars, light-duty trucks, and multipurpose passenger vehicles up to and including 4500 kg (10 000 lb) GVWR. The purpose of the test code is to evaluate brake system performance of vehicles in service for compliance with regulations. The test code is expected to be utilized as a basis for a brake evaluation conducted by State or Federal officials engaged in highway safety programs. The primary consideration is that this test requires a minimum of instrumentation, time, driver skill, and cost to conduct.
Standard
2013-06-12
This SAE Recommended Practice establishes a method of evaluating the structural integrity of the entire brake system of all passenger cars under extreme braking conditions. The main purpose of this document is to evaluate the structural integrity of a vehicle's braking system. However, other areas, such as the steering or suspension system, may also be evaluated during the test, providing that the criteria and procedure detailed in the following sections are not modified in any way. For repeatability, it is recommended that a brake apply device be utilized whenever possible, since it will eliminate the variations in application times and efforts of different operators.
Standard
2013-06-10
There is currently no requirement in place for aftermarket brake lining performance. NHTSA has indicated that the automotive aftermarket should take a proactive approach to come up with a standard test definition for lining evaluation. Many aftermarket manufacturers use dynamometer testing to evaluate lining performance, but there is currently not a common recognized method for on-vehicle lining screening. This procedure was created to provide a quick, on-vehicle test method for lining performance evaluation. This procedure is intended for use in passenger cars; multi purpose vehicles and light trucks with a gross vehicle weight less than 4535 kg(10 000 lb).
WIP Standard
2013-04-24
This test code establishes wheel-slip brake-control system capabilities with regard to: 1.1 vehicle stability, maneuverability, and system function on various road surface conditions, including variable friction surfaces as well as uniform friction surfaces; 1.2 vehicle stopping distance on various road surface conditions; 1.3 not covered by this SAE Recommended Practice are: a. radio frequency interference testing and b. extensive power consumption testing. This document establishes a uniform procedure for the road test of wheel- slip brake-control systems on passenger cars, trucks, buses, and combination vehicles.
Standard
2013-04-09
This SAE Recommended Practice presents service brake performance requirements for brake systems of all combinations of new passenger cars and new trailers (braked or unbraked) intended for roadway use (excluding special-purpose vehicles such as ambulances, hearses, etc.). Acceptable performance requirements are based on data obtained from SAE J134.
Standard
2013-04-09
This code provides a test procedure for obtaining and determining extremely high brake fluid temperature encountered in the brake system of a vehicle that is equipped with disc brakes. Vehicles in normal operation may or may not produce brake fluid temperatures that are obtained in this procedure. To establish a uniform procedure for obtaining and determining a maximum temperature of brake fluid in the automotive braking system of vehicles equipped with disc brakes. This procedure is a uniform means of heating the brakes and the brake fluid and is not a simulation of any other test procedure.
Standard
2013-04-09
This SAE Recommended Practice establishes a uniform procedure for the level road test of the brake systems of all combinations of new multipurpose passenger vehicles, new light-duty trucks up to and including 4500 kg (10 000 lb), and new passenger cars when coupled with new trailers (braked or unbraked).
Technical Paper
2013-04-08
Peter Ruecker
Secondary safety systems to protect occupants have attained a very high level over the past decades. Further improvements are still possible, but increasingly minor progress is only to be had with a high degree of effort. Today, integrated safety is the key aspect to improve overall safety in manifold accident situations. This is already implemented in the development of new cars. But so far, the testing and assessment of new cars still involves using tests which do not take into account the significant additional potential of integrated safety measures. An example is given with automatic pre-crash braking functions, which are newly available in state-of-the-art cars. Using reliable information on an imminent crash, such measures act already in the pre-crash phase and can result in a significantly high decrease of the accident outcomes. Such preventive measures are the key to a further substantial reduction of the figures of crash victims on our roads. This paper aims to illustrate the pre-crash braking approach for cars of the BMW 5 series.
Technical Paper
2013-04-08
Nantu Roy, Mark Villaire
The concept of full vehicle simulation has been embraced by the automobile industry as it is an indispensable tool for analyzing vehicles. Vehicle loads traditionally obtained by road load data acquisition such as wheel forces are typically not invariant as they depend on the vehicle that was used for the measurement. Alternatively, virtual road load data acquisition approach has been adopted in industry to derive invariant loads. Analytical loads prior to building hardware prototypes can shorten development cycles and save costs associated with data acquisition. The approach described herein estimate realistic component load histories with sufficient accuracy and reasonable effort using full vehicle simulations. In this study, a multi-body dynamic model of the vehicle was built and simulated over digitized road using ADAMS software, and output responses were correlated to a physical vehicle that was driven on the same road.
Technical Paper
2013-04-08
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. The secondary purpose was to explore various approaches for evaluating route equivalence.
Technical Paper
2013-04-08
Richard 'Barney' Carlson, Henning Lohse-Busch, Jeremy Diez, Jerry Gibbs
The U.S. Department of Energy's Office of Energy Efficiency & Renewable Energy initiated a study that conducted coastdown testing and chassis dynamometer testing of three vehicles, each at multiple test weights, in an effort to determine the impact of a vehicle's mass on road load force and energy consumption. The testing and analysis also investigated the sensitivity of the vehicle's powertrain architecture (i.e., conventional internal combustion powertrain, hybrid electric, or all-electric) on the magnitude of the impact of vehicle mass. The three vehicles used in testing are a 2012 Ford Fusion V6, a 2012 Ford Fusion Hybrid, and a 2011 Nissan Leaf. Testing included coastdown testing on a test track to determine the drag forces and road load at each test weight for each vehicle. Many quality measures were used to ensure only mass variations impact the road load measurements. Chassis dynamometer testing was conducted over standard drive cycles on each vehicle at multiple test weights to determine the fuel consumption or electrical energy consumption impact caused by change in vehicle mass.
Standard
2013-03-28
This SAE Recommended Practice establishes a uniform procedure for the level road test of the brake systems of new light-duty trucks and new multipurpose passenger vehicles up to and including 2700 kg (6000 lb) GVW and all classes of new passenger cars. The purpose of the test code is to establish brake system capabilities with regard to: a. Deceleration versus input, as affected by vehicle speed, brake temperature, and usage; b. brake system integrity; c. Stopping ability during emergency or inoperative power assist conditions; d. Water recovery characteristics.
Technical Paper
2012-11-25
Roland Sottek, Bernd Philippen
Besides powertrain and aerodynamic noise, tire-road noise is an important aspect of the acoustic comfort inside a vehicle. For the subjective evaluation of different tires or vehicles in a benchmark, authentic sound examples are essential. They should be recorded on a real road rather than on a roller dynamometer (avoiding artificial and periodic sounds, especially in the case of a small roller circumference and a smooth surface). The challenge of on-road measurements is the need for separating the components of the interior noise generated by rolling tires, aerodynamic flow and powertrain. This allows for individual judgment of the noise shares. A common approach for eliminating the engine sound is shutting the engine off after acceleration to the desired maximum speed. Operational Transfer Path Analysis (OTPA) can then be used to auralize the tire-road noise at a certain receiver location, where an artificial head records the interior noise during this coast-down. Further signals are needed which are measured with a triaxial accelerometer at each wheel carrier and microphones applied near the tires.
Standard
2012-05-23
This SAE Recommended Practice provides a road test procedure for trucks, truck-tractors, and buses to evaluate their compliance with Federal Motor Vehicle Safety Standards (FMVSS) 105 and 121; Hydraulic and Air Brake Systems. Units of measure are English in lieu of metric to be commensurate with FMVSS 105 and 121.
Technical Paper
2012-04-16
Duane R. Meyers, Thomas W. Parrott, Timothy P. Austin
Vehicles often rotate during traffic collisions due to impact forces or excessive steering maneuvers. In analyzing these situations, accident reconstructionists need to apply accurate deceleration rates for vehicles that are both rotating and translating to a final resting position. Determining a proper rate of deceleration is a challenging but critical step in calculating energy or momentum-based solutions for analytical purposes. In this research, multiple empirical tests were performed using an instrumented vehicle that was subjected to induced rotational maneuvers. A Ford Crown Victoria passenger car was equipped with a modified brake system where selected wheels could be isolated. The tests were performed on a dry asphalt surface at speeds of approximately 50 mph. In each of the tests, the vehicle rotated approximately 180 degrees with the wheels on one side being completely locked. During each run, the vehicle driver prevented steering input by maintaining control of the steering wheel.
Standard
2011-11-21
The purpose of this SAE Recommended Practice is to establish the specific criteria for the selection of a replacement refrigerant for mobile CFC-12 (R-12) air-conditioning (A/C) systems. This document provides guidelines for qualifying candidate refrigerant. The requirements include laboratory and field testing. The alternate refrigerant shall provide comparable system performance as CFC-12 (R-12) as defined herein. The vehicle testing shall be conducted on representative vehicle manufacturer's product line, in which the refrigerant is intended to be used, such as cycling clutch orifice tube, constant run orifice tube, cycling clutch expansion valve, or continuous run expansion valve refrigerant system. This document is complete only when combined with the requirements of SAE J1657.
Technical Paper
2011-05-17
Hiroshi Yamauchi
This paper shows some discussions regarding an experimental consideration of booming noise level when a vehicle drives over a small protruding object on a road. Booming noise level is subjected to vehicle speed and is not proportional to the speed. Generally, it is known as the maximal noise level is being created with vehicle speed of around 40 km/h, however, the obvious cause of the phenomena have not been completely determined so far. In this paper, at first, it shows an experimental data that was being observed in detail with variable vehicle speed. Based on our detailed observation of the experimental data, reversed-phase two inputs by existence of a protruding object, was confirmed. By considering correlation between time difference of two inputs and vehicle speed, it is demonstrated that those two inputs around 40km/h induce a tire resonance which leads to a booming noise in a cabin. We define it as ‘harsh booming noise’ here.
Technical Paper
2011-05-17
Albers Albert, Alexander Schwarz
The NVH (Noise Vibration Harshness) behavior of modern vehicles becomes more and more important - especially in terms of new powertrain concepts, like in hybrid electric or full electric vehicles. There are many tools and methods to develop and optimize the NVH behavior of modern vehicles. At the end of the development process, subjective ratings from road tests are very important. For objective analyses, different approaches based on artificial neural networks exist. One example is the AVL-DRIVE™ system, a driveability analysis and benchmarking system which allows, based on a very small set of sensors, an adequate objective rating of the vehicle's driveability. The system automatically detects driving maneuvers and rates the driveability. This article presents a method which is able not only to rate different maneuvers and the behavior of the vehicle but also to detect phenomena and causes in the domain of NVH. In terms of effort, one main requirement was to use the same sensor set as the driveability evaluation system and no additional equipment.
WIP Standard
2011-04-28
This recommended practice provides a standard test procedure for comparing the fuel economy of components or systems of the type which can be switched from one vehicle to another in a short period of time. This test procedure is also ideally suited for comparing the fuel consumption of one vehicle to another, and one component of a combination vehicle to the same component in another. This procedure is specifically designed to be completed in one day. The test utilizes two medium to heavy duty in-service vehicles operated over interstate type highways. The relative fuel economy of the component, system, or vehicle under test is expressed as a percentage improvement or as a percentage of fuel saved. This factor is calculated using relative fuel consumption while operating with and without the test component, system, or vehicle under evaluation. Accuracy obtained from the use of this test procedure can be +/-1% when properly executed. This procedure is not intended to replace SAE J1264 OCT86, Joint RCCC/SAE Fuel Consumption Test Procedure or SAE J1321 OCT86, Joint TMC/SAE Fuel Consumption Test Procedure Type II, but will enhance a fleet's or manufacturer's ability to do a wide variety of fuel consumption tests on highway.
Technical Paper
2011-04-12
Cwo Gee Liang
A simulation methodology is developed for the Constant Radius Constant Speed (CRCS) analysis to predict the ISO4138 [1] road test performance. The CRCS analysis can be used to predict the vehicle steady-state handling characteristics such as understeer, rear cornering compliance, and roll gradient, etc. The Yaw-Rate Control methodology is applied to replace the traditional driver-in-the-loop path-following approaches. Comparing to the path-following approaches, the proposed method is simpler to use, more efficient, accurate, and robust.
Technical Paper
2011-04-12
Adrian Philip Gaylard, Bradley Duncan
Numerical simulation of aerodynamics for vehicle development is used to meet a wide range of performance targets, including aerodynamic drag for fuel efficiency, cooling flow rates, and aerodynamic lift for vehicle handling. The aerodynamic flow field can also be used to compute the advection of small particles such as water droplets, dust, dirt, sand, etc., released into the flow domain, including the effects of mass, gravity, and the forces acting on the particles by the airflow. Previous efforts in this topic have considered the water sprays ejected by rotating wheels when driving on a wet road. The road spray carries dirt particles and can obscure the side and rear glazing. In this study, road sprays are considered in which the effects of additional water droplets resulting from splashing and dripping of particles from the wheel house and rear under body are added to help understand the patterns of dirt film accumulation on the side glass and rear glass. Results are compared to experimental photographs for both a sedan and an SUV tested using luminescent dye in a wind-tunnel as well as in road testing.
Technical Paper
2011-04-12
Daichi Katoh, Yoshimitsu Hashizume, Itsuhei Kohri, Michitosh Takagi
The aerodynamic performance of new vehicles is commonly determined using computational fluid dynamics (CFD) and wind tunnel tests. The final assessment is carried out by actual running tests. In particular, ideas regarding fuel consumption improvement that relate to components for the reduction of the coefficient of drag (CD) value are evaluated by coast-down tests. However, a difference often exists between the component's efficiency between wind tunnel tests and coast-down tests. Therefore, we focused on the efficiency of an air-dam spoiler in reducing CD values. A comparison was made between the aerodynamic effect of the air-dam spoiler in wind tunnel and coast-down tests in terms of the CD value and the wake structure behind the vehicle. To determine the relationship between the CD value and the wake structure behind the vehicle, we measured vehicle speed, wind velocity and direction, vehicle height, and pressure distribution on the back door. The results revealed that the CD values were reduced approximately 7% by attaching the air-dam spoiler in both the wind tunnel and coast-down tests.
Technical Paper
2009-12-13
Rajiv Kumar, Bharath K Suda, Sandeep Karande, Damrongrit Piyabongkarn, Chinmaya Patil
This paper discusses the effect of torque vectoring differential on improving vehicle handling and stability performance. The torque vectoring concept has been analyzed. The vehicle discussed in this paper is an AWD vehicle with torque vectoring differential in the rear and a torque biasing center differential. First, simulation results with vehicle model in CarSim® and torque vectoring control algorithm in Matlab®/Simulink® is discussed. Then, experimental results for vehicle tested at winter and summer test facility is presented. Both simulation and experimental results demonstrate the effectiveness of torque vectoring differential on vehicle handling & stability.
Technical Paper
2009-12-13
Sunny Agarwal, Jasbir Singh, Gaurav Kulshrestha
Compressed natural gas (CNG) is being explored as a sustainable renewable fuel for vehicles in India due to mounting foreign exchange expenditure to import crude petroleum. Impending emissions regulations for diesel engines, specifically exhaust particulate emissions have caused engine manufacturers to once again examine the potential of alternative fuels. Much interest has centered on compressed natural gas (CNG) due to its potential for low particulate and hydrocarbon based emissions. Natural gas engine development projects have tended toward the use of current gasoline engine technology (stoichiometric mixtures, closed-loop fuel control and exhaust catalysts). Significant amount of research and development work is being undertaken in India to investigate various aspects of CNG utilization in different types of engines. This paper discusses about the development of the bi-fuel CNG engine for passenger vehicular application. The impact of using CNG was studied in terms of cold start ability, drive-ability, acceleration, max speed, grade ability, fuel economy and exhaust emissions.
Technical Paper
2009-11-02
Kevin Walkowicz, Kwangsam Na, William Robertson, Keshav Sahay, Mike Bogdanoff, Chris Weaver, Richard Carlson
In order to demonstrate the performance of a retrofitted selective catalytic reduction (SCR) system while also addressing the issues associated with greater use of biodiesel, a 2005 International 9200i tractor owned by the City of Santa Monica was retrofitted with a titania-vanadia-tungsten catalyst and a urea dosing system supplied by Extengine Systems, Inc. This tractor was operated under normal service conditions within the City of Santa Monica refuse collection and transportation fleet. An on-board emissions measurement system supplied by Engine, Fuel, and Emissions Engineering, Inc. was installed on the vehicle; it measured the emissions and fuel use of the vehicle while it operated on ultra-low-sulfur diesel (ULSD), 20% biodiesel (B20), and 99% biodiesel (B99) on consecutive days. The vehicle, with a similar aftertreatment system, was then tested at the California Air Resources Board (CARB) Los Angeles Heavy-Duty Emissions Lab and tested on the Urban Dynamometer Driving Schedule (UDDS) to again assess the effects of ULSD, B20, and B99 on the performance of the urea-SCR aftertreatment system.
Technical Paper
2009-06-15
L. Cachón, D. Tóth, E. Pucher
An optimized monofuel CNG light duty vehicle based on the Opel Zafira was investigated under real-world conditions and the results are presented in this study. To analyze the real-world performance of the monofuel CNG vehicle due to fuel consumption and exhaust emissions representative experimental test on road-test routes were performed, including sections with significantly different driving conditions. Furthermore, driving tests at different constant speeds on freeway were carried out. A benchmarking to the same vehicle with diesel powertrain was done as well. The test vehicles were equipped with a new compact on-board measurement system and additionally GPS tracking to link the received geographic information of the road-test routes with the measured exhaust mass emission data. The measurement results were validated with Matlab Simulink models of the powertrain and vehicle.
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