Display:

Results

Viewing 1 to 30 of 435
2016-04-05
Technical Paper
2016-01-0272
Huairui Guo, David Dronzkowski
Vehicle level road test probably is the most important test before a vehicle model goes to mass production. Failures found during the test are fixed and reliability of the vehicle is then improved. This test-fix-test process is often called reliability growth test. To achieve effective reliability growth, two things are critical. One is how and under what condition vehicles are tested; the other is having a formal Failure Report and Corrective Action System (FRACAS) in place. The topic of this paper is related to the former. We will discuss methods of determining the proper road profiles used in reliability growth tests. The goal of a reliability growth test is to find failures that customers will be experiencing and fix them. Therefore the road profiles used in the test should represent how actual customer usage. This data is typically compiled using customer surveys.
2016-04-05
Technical Paper
2016-01-0120
Libo Huang, Huanlei Chen, Zhuoping Yu, Jie Bai
Automotive radar is the most important component in the autonomous driving system, which detects the obstacles, vehicles and pedestrians around with acceptable cost. The target tracking is one of the key functions in the automotive radar which measures the position and velocity of the targets. Modern automotive radar requires a multi-target tracking algorithm, as in the radar field of view, hundreds of targets can present. In the vehicle field test, the automotive monopulse radar faces very complicated and fast-changing road conditions, which include tunnels and curved roads. The curved tunnel walls work like mirrors which reflect the electromagnetic waves coming out from the radar and reflected by the targets. The unreal targets, which are generated by the reflected electromagnetic waves by the walls instead of the direct waves, must be well identified by the radar peak detection. Multiple reflections by the parallel tunnel walls create many unreal targets.
2016-04-05
Journal Article
2016-01-0459
Jian Zhao, Jing Su, Bing Zhu, Jingwei Shan
Indirect Tire Pressure Monitoring System (TPMS) is a system which monitors the tire pressure based on the wheel speed signals from Anti-lock Brake System (ABS). In this paper, a practical indirect TPMS method is proposed to estimate the tire pressure according to the relationship between the tire pressure and the tire circumferential vibration. Firstly, the error of ABS wheel speed sensor system caused by the machining tolerance of the tooth ring are estimated based on the measured wheel speed using Recursive Least Squares algorithm. Then, the measuring error is eliminated and the vibration noise is further extracted from the from the wheel speed signal. Using the vibration noise, the resonance frequency of the tire vibration system was extracted by Maximum Entropy Spectral Estimation (MESE) based on Auto-regressive (AR) model.
2016-04-05
Technical Paper
2016-01-1594
Petter Ekman, Roland Gardhagen, Torbjorn Virdung, Matts Karlsson
Considerable amounts of the everyday goods transport in Sweden is done with light trucks. In the last ten years (2005-2015) the number of light trucks has increased by 33% in Sweden. The majority of these light trucks are fitted with a swapbody, and encounter the same problem as many other truck configurations, namely that several different manufacturers contribute to the final shape of the vehicle. Due to this, the aerodynamics of the final vehicle is often not fully considered, hence there appear to be room for improving the aerodynamic performance. The flow around a light truck fitted with a swapbody has been investigated with use of Computational Fluid Dynamics (CFD). Focus has been on improving the swapbody shape in order to reduce the aerodynamic drag and the fuel consumption, but still keeping it usable for daily operations.
2016-02-01
Technical Paper
2016-28-0201
Upendra Kulkarni, Monish M. H. Gowda, Hima Kiran Venna
Abstract Steering and suspension system has to be designed properly to achieve improved handling characteristics. Improper design of steering systems will result in steering errors such as bump steer and roll steer. These steering errors results in reduced steering performance. During the design of steering system the tie rod length has to be properly selected to reduce these steering errors. The purpose of the work is to analyze the effects of tie rod length variation on bump steer. Multi body dynamic model of the selected vehicle was created using MSC ADAMS Car software. Ideal design of steering system to achieve zero bump steer was created. The tie rod length was later varied up to 10% to study the effect of varying length on bump steer. Parallel wheel travel analysis was conducted to study the tie rod length variation on bump steer. Acceleration test was conducted on a flat road having bump to analyze the effect of changing tie rod length on steering performance of the vehicle.
2016-01-04
WIP Standard
J1293
This document is a road test procedure for comparing the corrosion resistance of both coated and uncoated sheet steels in an undervehicle deicing salt environment.
2015-11-25
WIP Standard
J3115
This document aims to establish best practices in equipment setup and measurement of brake rotor disk thickness variation (DTV) on vehicle.
2015-04-14
Journal Article
2015-01-1166
Elena Paffumi, Michele De Gennaro, Giorgio Martini, Urbano Manfredi, Stefano Vianelli, Fernando Ortenzi, Antonino Genovese
Abstract The experimental measurement of the energy consumption and efficiency of Battery Electric Vehicles (BEVs) are key topics to determine their usability and performance in real-world conditions. This paper aims to present the results of a test campaign carried out on a BEV, representative of the most common technology available today on the market. The vehicle is a 5-seat car, equipped with an 80 kW synchronous electric motor powered by a 24 kWh Li-Ion battery. The description and discussion of the experimental results is split into 2 parts: Part 1 focuses on laboratory tests, whereas Part 2 focuses on the on-road tests. As far as on-road tests are concerned, the vehicle has been tested over three different on-road routes, ranging from 60 to 90 km each, with a driving time ranging from approximately one and half to two and half hours.
2015-04-14
Technical Paper
2015-01-1543
Petter Ekman, Roland Gårdhagen, Torbjörn Virdung, Matts Karlsson
Abstract Road transportation by trucks is the major part of the goods transportations system in the European Union (EU), and there is a need for increased fuel efficiency. While truck manufacturers already spend significant resources in order to reduce the emissions from their vehicles, most truck manufacturers do not control the shape of the trailer and/or swap bodies. These devices are usually manufactured by different companies that cannot consider the overall aerodynamics around the complete vehicle. By use of Computational Fluid Dynamics (CFD) and previous wind tunnel experiments, the flow around a simplified generic tractor-trailer model has been investigated. With better understanding of the flow features around the tractor with attached trailer or swap bodies, an improved design of the trailer and swap body can be achieved, which is the aim for the project.
2015-03-13
Standard
J3018_201503
This document provides guidelines for the safe conduct of on-road tests of vehicles equipped with prototype conditional, high, and full (levels 3-5) automated driving systems (ADSs), as defined by SAE J3016. It does not include guidance for testing production ADSs intended for sale to the general public. The scope is further limited to testing of automated prototype vehicles on public roads. These guidelines do not address: • Testing of driver assist (Level 1) or partial (Level 2) automation systems, which rely on a human driver to monitor the environment. (See SAE J3016 for Definitions of Levels of Automated Systems.) • Closed-course testing. • Component-level testing. The precise regime of road testing for a particular prototype will depend on the intended level of automation and the targeted capabilities of the prototype (see SAE J3016 for more information).
2015-01-14
Technical Paper
2015-26-0160
Adria Ferrer, Stefanie de Hair, Oliver Zander, Rikard Fredriksson, Swen Schaub, Frederic Nuss, Marie Caspar
Abstract Pedestrians and cyclists are the most unprotected road users and their injury risk in case of accidents is significantly higher than for other road users. The understanding of the influence and sensitivity between important variables describing a pedestrian crash is key for the development of more efficient and reliable safety systems. This paper reflects the related work carried out within the AsPeCSS project. The results summarized out of virtual and physical tests provide valuable information for further development. 1168 virtual and 120 physical tests were carried out with adult and child pedestrian headform as well as upper and lower legform impactors representatives of 4 different vehicle front geometries in a wide range of impact speeds, angles and locations. This test matrix was based on previous work carried out within the AsPeCSS project.
2014-10-01
Journal Article
2014-01-9030
Sermet Yucel, Melinda Moran Lucking, Jon Magnuson, Germana Paterlini, Benjamin Worel
Fuel economy and performance vary significantly with the vehicle design and configuration, road profile, and payload. The variation is more pronounced for heavy-duty trucks and understanding its origin is critical to maximizing fleet profitability. In this paper we demonstrate a method to continuously estimate fuel consumption breakdown over resistive forces while the vehicle is driven on a public highway. The method is fast, cost-effective, and capable of analyzing trip segments as short as one second. The method utilizes a non-linear Kalman filter and a vehicle dynamical model that has a coupled longitudinal and vertical motion. The paper presents the breakdown of fuel consumption and an estimate of road grade profile obtained by driving a heavy-duty vehicle at the MnROAD research facility in Albertville MN.
2014-09-28
Technical Paper
2014-01-2526
Kenneth D. Norman, Amandeep Singh
Abstract Assessment of braking performance that includes brake fade is a critical part of the evaluation of military light tactical vehicles as it is for conventional light cars and trucks. These vehicles are sometimes called upon to operate in severe mountain regions that challenge the braking performance well beyond the environment in which these vehicles are normally operated. The U.S. Army Test Operating Procedure (TOP) 2-2-608 includes a test schedule conducted in the mountainous region near Jennerstown, Pennsylvania. While this test procedure represents a typical mountain environment, it does not represent the most severe mountain descents that can be encountered across the United States. As a preliminary step to developing a representative severe mountain descent braking test, mountain roads throughout the United States were evaluated analytically to identify potential test venues.
2014-05-16
Standard
J1247_201405
This SAE Recommended Practice establishes a uniform procedure for a flat-road simulation of a mountain-fade test of the brake systems of light-duty trucks and multipurpose passenger vehicles up to and including 4500 kg (10 000 lb) GVW and all classes of passenger cars. The purpose of this test code is to establish brake system characteristics while simulating a mountain descent. This procedure is intended to be used to evaluate the following characteristics of a brake system: a. Brake temperature relative to fluid boil b. Fade resistance and reserve pedal travel c. Overall structural durability d. Subjective stability
2014-04-01
Technical Paper
2014-01-1848
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.
2014-04-01
Technical Paper
2014-01-1977
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.
2014-04-01
Technical Paper
2014-01-0466
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.
2014-04-01
Journal Article
2014-01-0484
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.
2013-07-24
Standard
J201_201307
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.
2013-06-12
Standard
J229_201306
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.
2013-06-10
Standard
J2624_201306
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).
2013-04-24
WIP Standard
J46
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.
2013-04-09
Standard
J291_201304
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.
2013-04-09
Standard
J134_201304
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).
2013-04-09
Standard
J135_201304
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.
2013-04-08
Technical Paper
2013-01-0200
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.
Viewing 1 to 30 of 435

Filter