Criteria

Text:
Display:

Results

Viewing 241 to 270 of 15290
2016-04-05
Technical Paper
2016-01-0474
Shukai Yang, Bingwu Lu, Zuokui Sun, Yingjie Liu, Hangsheng Hou
Abstract A low frequency vibration issue around 3.2 Hz occurs during a commercial heavy truck program development process, and it is linked to extremely uncomfortable driving and riding experiences. This work focuses on an analytical effort to resolve the issue by first building a full vehicle MBS (multi-body-system) model, and then carrying out vibration response analyses. The model validation is performed by using full vehicle testing in terms of structural modes and frequency response characteristics. In order to resolve the issue which is excited by tire non-uniformity, the influence of the cab suspension, frame modes, front leaf spring system and rear tandem suspension is analyzed. The root cause of the issue is found to be the poor isolation of the rear tandem suspension system. The analytical optimization effort establishes the resolution measure for the issue.
2016-04-05
Technical Paper
2016-01-0464
Lingyang Li, Wei Wu, Ji Chen, Jianpeng Shi, Xicheng Wang, Liuhua Qian
Abstract In order to expand the product design and development capabilities of Electric Power Steering (EPS) system, a passenger car’s simulation model integrated with EPS system model will be made. Some analytical investigation is conducted in this paper. Through simplifying the architecture model of EPS system, the mathematical equation expressions of steering wheel and column, worm gear reducer, rack and pinion, steer-wheels, brushed DC electrical motor, and ECU assistance and compensation laws will be described. A number of tests on the EPS full system and subsystems and components will be executed. The tests’ results will be used as the input parameters of the model, and then be used for model validations. After that, the EPS system model will be created. Since the most important part of control logic strategy is the top secret of steering assembly supplier and it could’t be provided to OEM in details or not even a black-box model directly.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Abstract Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Technical Paper
2016-01-0503
Evandro Giuseppe Betini, Francisco Carlos Cione, Cristiano Stefano Mucsi, Marco Antonio Colosio, Jesualdo Luiz Rossi, Marcos Tadeu D'Azeredo Orlando
Abstract This paper reports the experimental efforts in recording the 2-dimensional temperature distribution on autogenous thin plates of UNS S32304 steel during welding. The butt-welded autogenous joints were experimentally performed by the GTAW (Gas Tungsten Arc Welding) process with either argon or argon-2%nitrogen atmospheres. The temperatures cycles were recorded by means of thermocouples embedded by spot welding on the plate's surfaces and connected to a multi-channel data acquisition system. The laser flash method (LFM) was also used for the determination thermal diffusivity of the material in the thickness direction. The temperature curves suggest a relationship between the microstructures in the solidified and the heat affected zone with the diffusivity variation. This is a region where there had been a major incidence of heat. The obtained results validate the reliability of the experimental used apparatus.
2016-04-05
Technical Paper
2016-01-0201
Armin Traussnig, Wilko Jansen, Heinz Petutschnig, Sepp Steiner, Petra Gruen
Abstract In order to meet current and future emission and CO2 targets, an efficient vehicle thermal management system is one of the key factors in conventional as well as in electrified powertrains. Global vehicle simulation is already a well-established tool to support the vehicle development process. In contrast to conventional vehicles, electrified powertrains offer an additional challenge to the thermal conditioning: the durability of E-components is not only influenced by temperature peaks but also by the duration and amplitude of temperature swings as well as temperature gradients within the components during their lifetime. Keeping all components always at the preferred lowest temperature level to avoid ageing under any conditions (driving, parking, etc.) will result in very high energy consumption which is in contradiction to the efficiency targets.
2016-04-05
Technical Paper
2016-01-1600
Pruthviraj Mohanrao Palaskar, Vivek Kumar, Rohit Vaidya
Abstract Important vehicle performance parameters such as, fuel economy and high speed stability are directly influenced by its aerodynamic drag and lift. Wind tunnel testing to asses these parameters requires heavy investment especially when test wind tunnel is not available in the country where vehicle development center is present. Hence to save cost and to compress development time, it is essential to asses and optimize parameters of a vehicle in very early stages of development. Using numerical flow simulations optimization runs can be carried out digitally. Industry demands prediction of aerodynamic drag and lift coefficients (CD,CL) within an accuracy of a few counts, consuming minimal HPC resources and in a short turnaround time. Different OEMs deploy different testing methods and different softwares for numerical simulations.
2016-04-05
Technical Paper
2016-01-1594
Petter Ekman, Roland Gardhagen, Torbjorn Virdung, Matts Karlsson
Abstract Considerable amounts of the everyday goods transports are done using 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 swap body 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 appears to be room for improving the aerodynamic performance. In this study the flow around a swap body fitted to a light truck has been investigated using Computational Fluid Dynamics. The focus has been on improving the shape of the swap body in order to reduce both the aerodynamic drag and fuel consumption, while still keeping it usable for daily operations.
2016-04-05
Technical Paper
2016-01-0146
Yonghwan Jeong, Seonwook Kim, Kyongsu Yi, Sangyong Lee, ByeongRim Jo
Abstract This paper represents a parking lot occupancy detection and parking control algorithm for the autonomous valet parking system. The parking lot occupancy detection algorithm determine the occupancy of the parking space, using LiDAR sensors mounted at each side of front bumper. Euclidean minimum spanning tree (EMST) method is used to cluster that information. After that, a global parking map, which includes all parking lots and access road, is constructed offline to figure out which cluster is located in a parking space. By doing this, searching for available parking lots has been finished. The proposed parking control algorithm consists of a reference path generation, a path tracking controller, and a parking process controller. At first, route points of the reference path are determined under the consideration of the minimum turning radius and minimum safety margin with near parking.
2016-04-05
Technical Paper
2016-01-0029
Chuanliangzi Liu, Bo Chen, Ming Cheng, Anthony Champagne, Keyur Patel
Abstract The Electronic Control Unit (ECU) of an Electric Power Steering (EPS) system is a core device to decide how much assistance an electric motor applies on a steering wheel. The EPS ECU plays an important role in EPS systems. The effectiveness of an ECU needs to be thoroughly tested before mass production. Hardware-in-the-loop simulation provides an efficient way for the development and testing of embedded controllers. This paper focuses on the development of a HiL system for testing EPS controllers. The hardware of the HiL system employs a dSPACE HiL simulator. The EPS plant model is an integrated model consisting of a Vehicle Dynamics model of the dSPACE Automotive Simulation Model (ASM) and the Nexteer Steering model. The paper presents the design of an EPS HiL system, the simulation of sensors and actuators, the functions of the ASM Vehicle Dynamics model, and the integration method of the ASM Vehicle Dynamics model with a Steering model.
2016-04-05
Technical Paper
2016-01-0052
Jihas Khan
Abstract HILS is a proven and essential part of the embedded product development life cycle which strives to reduce effort, time and cost spent on automotive validation activities. An efficient HILS system allows to create a precise simulation environment for the ECU which is made to believe that it is sitting inside a real vehicle and there by the intended functionalities implemented in the same could be tested even before the vehicle prototypes or other ECUs or sensors and actuators are available. An inefficient and faulty HILS system provides erroneous test results which could lead to wrong inferences. This paper is proposing a standardized process flow aided by specific documentation and design concepts which validates that the test system designed is robust and caters to the actual requirement. The Design stage starts by a requirement gathering phase where the analysis of the device under test is executed in detail.
2016-04-05
Technical Paper
2016-01-0099
Deepak Venkatesh, Arockia Selvakumar
Abstract The concept of camless engines enables us to optimize the overall engine efficiency and performance, as it provides great flexibility in valve timing and valve displacement. This paper deals with design of camless engines with pneumatic actuator. The main objective is to build a prototype and test its performance at different engine speeds. Also an extensive research on the sensors is done to detect the various sensors that could be used to identify the crankshaft position. Here the features and advantages over conventional engines are discussed. In addition the overview of the camless system in the engine is focused along with the design principle and the components used. The system thus designed is capable of actuating at 1500 rpm and demonstrates the ability of pneumatic actuators to be used in an internal combustion engine with low rpm needs.
2016-04-05
Technical Paper
2016-01-0419
Whitney Poling, Vesna Savic, Louis Hector, Anil Sachdev, Xiaohua Hu, Arun Devaraj, Fadi Abu-Farha
Abstract The strain-induced diffusionless shear transformation of retained austenite to martensite during straining of transformation induced plasticity (TRIP) assisted steels increases strain hardening and delays necking and fracture leading to exceptional ductility and strength, which are attractive for automotive applications. A novel technique that provides the retained austenite volume fraction variation with strain with improved precision is presented. Digital images of the gauge section of tensile specimens were first recorded up to selected plastic strains with a stereo digital image correlation (DIC) system. The austenite volume fraction was measured by synchrotron X-ray diffraction from small squares cut from the gage section. Strain fields in the squares were then computed by localizing the strain measurement to the corresponding region of a given square during DIC post-processing of the images recorded during tensile testing.
2016-04-05
Technical Paper
2016-01-0417
Wan Xu, Xinfeng Shi, Tian Bai, Guobiao Yang, Lianxiang Yang, Changqing Du, Dajun Zhou, Yongjun Zhou
Abstract In Aluminum Alloy, AA, sheet metal forming, the through thickness cracking at the edge of cut out is one of the major fracture modes. In order to prevent the edge cracking in production forming process, practical edge stretch limit criteria are needed for virtual forming prediction and early stamping trial evaluations. This paper proposes new methods for determining the edge stretching limit of the sheet coupons, with and without pre-stretching, based on the Digital Image Correlation (DIC) technique. A numbers of sets of notch-shaped smaller coupons with three different pre-stretching conditions (near 5%, 10% and fractured) are cut from the prestretched large specimens. Then the notch-shaped smaller coupons are stretched by uniaxial tension up to through edge cracking observed. A dual-camera 3D-DIC system is utilized to measure both coupon face strain and thickness strain in the notch area at the same time.
2016-04-05
Technical Paper
2016-01-0123
Mostafa Anwar Taie, Mohamed ElHelw
Abstract The evaluation of Advanced Driver Assistance Systems (ADAS including driver assistance and active safety) has increasing interest from authorities, industry and academia. AsPeCSS active safety project concludes that good results in a laboratory test for active safety system design does not necessarily equate to an effective system in real traffic conditions. Moreover, many ADAS assessment projects and standards require physical testing on test tracks (dummy vehicles, pedestrian mannequins…), which are expensive and limit testing capabilities. This research presents a conceptual framework for on-board evaluation (OBE) of ADAS, which can be used as a cost effective evaluation in real-life traffic conditions. OBE shall monitor, record, analyze and report both internal behavior and external environment (external objects list and video stream) of ADAS under evaluation (ADASUE).
2016-04-05
Technical Paper
2016-01-0120
Libo Huang, Huanlei Chen, Zhuoping Yu, Jie Bai
Abstract 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 estimates the position and speed of the targets having regarding to the measurement inaccuracy and interferences. Modern automotive radar requires a multi-target tracking algorithm, as in the radar field of view hundreds of targets can present. In practice, the automotive radar faces very complicated and fast-changing road conditions, for example tunnels and curved roads. The targets’ unpredictable movements and the reflections of the electromagnetic wave from the tunnel walls and the roads will make the multi-target tracking a difficult task. Such situation may last several seconds so that the continuous tracks of the targets cannot be maintained and the tracks are dropped mistakenly.
2016-04-05
Technical Paper
2016-01-1622
Miroslav Mokry
Abstract Lagally’s theorem is used to evaluate the increments to aerodynamic forces on automotive models, tested in solid-wall wind tunnels. The strengths of the model-representing singularities, pre-requisite for the application of the theory, are obtained from experimental wall pressure data, using an influence matrix method. The technique is demonstrated on the drag force acting on full-size and half-size truck models, measured in the same test section.
2016-04-05
Technical Paper
2016-01-1588
Abdalla Abdel-Rahman, Martin Agelin-Chaab, Gary Elfstrom, John Komar
Abstract Wind tunnels with integrated aerodynamic and thermodynamic testing with yaw capabilities are not common. In this study however, an integrated aerodynamic and thermodynamic testing system with yaw capabilities is developed and applied in the climatic wind tunnel at the University of Ontario-Institute of Technology (UOIT). This was done by installing an incremental force measuring system (FMS) on the large turntable that features a chassis dynamometer. The testing system was utilized to implement an integrated aero-thermal test on a full-scale race car. An efficient testing protocol was developed to streamline the integrated testing process. The FMS was used to enhance the test car’s stability, cornering speed, and fuel efficiency by using aerodynamic devices. These objectives were achieved by installing a high rear wing to increase the rear downforce, a modified front splitter extension to produce a front downforce gain, and front canards to contribute to drag reduction.
2016-04-05
Technical Paper
2016-01-0410
Joseph V. Gabiniewicz, Douglas M. Baker, Michael Testani
Abstract Historically, driveshaft torque data has been obtained using slip rings. Slip rings, however, are expensive, and require time-intensive driveshaft modifications for proper installation. In addition, the time and expense involved in field servicing units is prohibitive. For these reasons, AISIN Technical Center of America (ATCA) investigated a viable telemetry solution. At the onset of this development activity, existing torque telemetry solutions had their own issues. In particular, they did not offer the same data resolution as slip rings, they lacked sufficient battery life for long-term, real-world testing applications, and they suffered from data drop-outs. ATCA worked with TECAT Performance Systems to develop a torque telemetry solution that addressed all of these issues. This paper presents the development activity involved, alongside real-world measurement data showing the results of both the slip ring and telemetry solutions.
2016-04-05
Technical Paper
2016-01-0323
Sashank Mani Vedula, Nabal Kishore Pandey, KumarPrasad Tellikepalli, Satish Thimmalapura
Abstract OEMs these days are focusing on front loading the activities to Virtual Test Environment (VTE) based development owing to high development cost and complexity in achieving repeatability during testing phase of vehicle development,. This process not only helps in reducing the cost and time but also helps in increasing the maturity and confidence level of the developed system before actual prototype is built. In the past, extensive research has happened for increasing the fidelity of VTE by improving plant model efficacy which involves powertrain and other vehicle systems. On the other hand, improving the precision of driver model which is one of the most complex nonlinear systems of virtual environment still remains a challenge. It is apparent that various drivers show different behavior in real world for a given drive profile. While modelling a driver for a VTE, the real world driver attributes are seldom considered.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
Abstract In order to accurately predict product reliability, it is best to design a test in which many specimens are tested for a long duration. However, this scenario is not often practical due to economic and time constraints. This paper describes a reliability test in which a limited number of specimens are tested with little time remaining before the scheduled start of production. During the test, an unexpected failure mode that can be mitigated through a product redesign occurs. Because the scheduled start of production is near, there is not enough time to perform a test with redesigned specimens, so the current test proceeds as planned. We discuss several methods and the associated assumptions that must be made to account for the presence of the unexpected failure mode in the test data in order to make predictions of reliability of the redesigned product.
2016-04-05
Technical Paper
2016-01-0272
Huairui Guo, David Dronzkowski
Abstract Pre-production vehicle validation is a critical step in understanding what potential issues end customers may find. Road profiles used in vehicle level tests are critical in finding failures. Clearly, if all the vehicles are tested only on highway, many failures will not be discovered. Therefore, using the right road profiles is very important. Traditionally, customer survey data is used to identify an appropriate road profile by defining a route that represents the Xth percentile customer. In this paper, a clustering method is applied to group all the customers into several groups. Each group is represented by a single road profile, and the entire customer population can be represented by multiple road profiles. If vehicles are tested using these profiles, then the road test can better represent the field condition, and hopefully failures can be discovered more efficiently.
2016-04-05
Technical Paper
2016-01-1607
David Soderblom, Per Elofsson, Ann Hyvärinen
Abstract The effect of blockage due to the presence of the wind tunnel walls has been known since the early days of wind tunnel testing. Today there are several blockage correction methods available for correcting the measured aerodynamic drag. Due to the shape of the test object, test conditions and wind tunnel dimensions the effect on the flow may be different for two cab variants. This will result in a difference in the drag delta between so-called open-road conditions and the wind tunnel. This makes it more difficult to evaluate the performance of two different test objects when they are both tested in a wind tunnel and simulated in CFD. A numerical study where two different cab shapes were compared in both open road condition, and in a digital wind tunnel environment was performed.
2016-04-05
Technical Paper
2016-01-0048
Sundaravadivelu Kandavelu, Anil Kumar Velagapudi, Raghavendra Nese, Satish Thimmalapura
Abstract The effort involved in automotive software test/calibration at road level is very high and cost involved is also commendable because of the involved proto level samples. Further the on-road test/calibration process is sensitive to external factors like drive pattern and environmental conditions. It is always a challenge for any OEM, to come up with an efficient process, which optimizes development cost, time and reliability of the product. The model based test/calibration process is always a dream for any engineer to work on, as it has big advantage of cost, reproducibility and repeatability of test cases [1]. But the challenge lies in achieving the closeness to reality with limited availability of crucial data for model parameterization. Activity at test bed level bridges the gap between the on-road and model based test/calibration achieving high maturity level at optimal cost/time. Current vehicle has many systems, which work in synergy to create an impact on end customer.
2016-04-05
Technical Paper
2016-01-1573
Ken Archibald, Kyle Archibald, Donald Neubauer
Abstract This paper will document a rationale for wheel straightening based on the rise of declining roads, increased consumer preference for lower profile tires, unintended consequences of wheel customization and the reduction in energy consumption. A recommended patented procedure detailing how A356-T6 wheels can be straightened will be presented. To validate the recommended procedure a sample of wheels was uniformly deformed and straightened and subsequently tested per SAE J328 and SAE J175. Test results are provided that indicate straightened wheels should be fully serviceable in their intended service. A laboratory protocol to replicate the wheel flange cracks is described. The protocol is used to demonstrate that wheels without deformations do not result in flange cracks. Conversely wheels with deformations in excess of 1.5mm do result in cracks at less than 750,000 cycles.
2016-04-05
Technical Paper
2016-01-0496
Leonardo Farfan-Cabrera, Ezequiel A. Gallardo
Abstract Debris are progressively generated just after wear occurred by the interaction of various mechanical elements inside the engines, steering gear boxes, transmissions, differentials, etc. Besides, debris could interfere with the normal operation of such components generating even more damage in other parts due to three-body abrasion. Hence, dynamic seals are susceptible to interact with very fine debris accumulated in the working lubes. Recently, owing to many test advantages, the micro-scale abrasion test has been extensively used to reproduce three-body abrasion in hard materials, coatings, polymers, etc., however, it has not been before employed for the wear assessment of elastomeric materials. This paper presents an adaptation of the micro-scale test method to study three-body abrasive behavior of an elastomeric dynamic seal (samples extracted from an automotive commercial Acrylonitrile-butadiene NBR rotary seal) under lubricated conditions.
2016-04-05
Technical Paper
2016-01-0766
Tongyang Gao, Marko Jeftic, Geraint Bryden, Graham Reader, Jimi Tjong, Ming Zheng
Abstract The control of nitrogen oxide and smoke emissions in diesel engines has been one of the key researches in both the academia and industry. Nitrogen oxides can be effectively suppressed by the use of exhaust gas recirculation (EGR). However, the introduction of inert exhaust gas into the engine intake is often associated with high smoke emissions. To overcome these issues there have been a number of proposed strategies, one of the more promising being the use of low temperature combustion enabled with heavy EGR. This has the potential to achieve simultaneously low emissions of nitrogen oxide and smoke. However, a quantitative way to identify the transition zone between high temperature combustion and low temperature combustion has still not been fully explored. The combustion becomes even more complicated when ethanol fuel is used as a partial substitution for diesel fuel.
2016-04-05
Technical Paper
2016-01-0796
Ashish Shah, Per Tunestal, Bengt Johansson
Abstract This article presents a study related to application of pre-chamber ignition system in heavy duty natural gas engine which, as previously shown by the authors, can extend the limit of fuel-lean combustion and hence improve fuel efficiency and reduce emissions. A previous study about the effect of pre-chamber volume and nozzle diameter on a single cylinder 2 liter truck-size engine resulted in recommendations for optimal pre-chamber geometry settings. The current study is to determine the dependency of those settings on the engine size. For this study, experiments are performed on a single cylinder 9 liter large bore marine engine with similar pre-chamber geometry and a test matrix of similar and scaled pre-chamber volume and nozzle diameter settings. The effect of these variations on main chamber ignition and the following combustion is studied to understand the scalability aspects of pre-chamber ignition. Indicated efficiency and engine-out emission data is also presented.
2016-04-05
Technical Paper
2016-01-1042
Jan Macek, Oldrich Vitek
Abstract The boost pressure demands call for high efficiency turbochargers. Perfect matching to an engine and controlling in operation is a prerequisite, especially if highly diluted mixture is used. The main impact on four-stroke engine efficiency is performed via gas exchange work, Correct turbocharger representation, usually performed by maps, should be delivered by turbocharger manufacturers and applied in simulation optimizations. The robust calibration methods are required for fast-running real time simulations used for model-based control. The paper clarifies the relations between apparent and real turbocharger isentropic efficiencies at steady-flow testbed and their impact on engine cycle optimization by simulation. Simple procedures excluding the impact of heat transfer inside a turbocharger are described. The described methods are based on the use of overall turbocharger efficiency.
2016-04-05
Technical Paper
2016-01-1108
Gordon McIndoe, Joseph VanSelous, Tongxiao Liu, Jeffrey David
Abstract A comparison of overall transmission efficiency, under normal vehicle operating conditions, is made between a production multi-mode CVT and a prototype multi-mode VariGlide CVT. The comparison is made through a combination of test data and simulation. A production passenger car with a stock multi-mode belt-type CVT was tested and evaluated for overall efficiency. Similarly a multi-mode VariGlide CVT had been previously built, tested and modeled. Through a combination of test data and model simulation an optimized configuration of the Variglide transmission was compared to the test results of the production transmission. The results show that when the VariGlide equipped transmission is splitting power between the VariGlide CVT and the mechanical path, significant improvements in overall transmission and vehicle efficiency can be achieved versus the stock CVT.
2016-04-05
Technical Paper
2016-01-1072
Peter Schaal, Byron Mason, Sotiris Filippou, Ioannis Souflas, Mark Cary
Abstract The paper presents a measurement methodology which combines a fine-wire thermocouple with input reconstruction in order to measure crank angle resolved temperature in an engine air-intake system. Thermocouples that are of practical use in engine experiments tend to have a large time constant which affects measurement accuracy during rapid temperature transients. Input reconstruction methods have previously been applied to thermocouples but have not been specifically used in combination with an ultra-thin uninsulated wire thermocouple to investigate cyclic intake temperature behavior. Accurate measurement results are of interest to improve the validity of many crank-angle resolved engine models. An unshielded thermocouple sensor has been developed which is rigid enough to withstand the aerodynamic forces of the intake air.
Viewing 241 to 270 of 15290