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Viewing 181 to 210 of 10679
2016-04-05
Technical Paper
2016-01-0445
Brian Paul Wiegand
Abstract Evaluation of the performance potential of an automotive conceptual design requires some initial quantitative estimate of numerous relevant parameters. Such parameters include the vehicle mass properties, frontal and plan areas, aero drag and lift coefficients, available horsepower and torque, and various tire characteristics such as the rolling resistance coefficient(s)… A number of rolling resistance models have been advanced since Robert William Thomson first patented the pneumatic rubber tire in 1845, most of them developed in the twentieth century. Most early models only crudely approximate tire rolling resistance behavior over a limited range of operation, while the latest models overcome those limitations but often at the expense of extreme complexity requiring significant computer resources.
2016-04-05
Technical Paper
2016-01-0446
Chen Liang, Guolin Wang, Zhou Zheng
Abstract A 3D finite element (FE) model of a radial tire 205/55R16, established using ABAQUS software, is utilized to simulate tire force and moment properties. Drum tests are designed to validate the FE model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented. Based on string balance contour theory, it simplifies the shape of belt pressure share ratio as a trapezium. Besides, a program for calculating tire contour curve is compiled using MATLAB software. Applying different belt pressure share ratios, diverse tire contours are designed. One of the contours is selected according to its positive effect on cornering stiffness in simulation.
2016-04-05
Technical Paper
2016-01-0451
Fu Wenkui, Liu Ligang, Shu Jin, Wang Dawei, Xu Long
Abstract Virtual Road Load Data Acquisition (vRLDA) is to replace traditional Road Load Data Acquisition (RLDA) thus becomes the important method to obtain the load for the fatigue analysis of the vehicle components. Pothole event, which is a typical loadcase among vehicle durability test in the development process, is simulated based on Adams/Car in this paper. Flex-body is adopted in the full vehicle model in order to improve the simulation accuracy. Flexible ring tire model, FTire, is used for the benefit of validity in higher frequency domain. The result shows that simulation result correlated well both in wheel center travel and load of tire and suspension parts. Consequently, it is available to predict the max effective jounce travel and body max load in the early phase of vehicle development thus decrease the potential risk in the later phase and the total research cost. vRLDA is also proven as a reliable and effective method to obtain the load.
2016-04-05
Technical Paper
2016-01-0441
Aref M. A. Soliman
Abstract An active suspension system has better performance than a passive suspension. However, it requires a significant amount of energy and is constructed from high cost components. To solve the problem of the power required, a switchable damper suspension system has been studied. In this paper, control strategies for the switchable damper suspension system and passive are compared in terms of their relative ride performance capabilities. Practical limitations involving switching time delay and threshold delay values are modeled and their effect on the ride performance are evaluated. The four setting switchable damper is compared with the two and three setting switchable dampers. The control strategies are used to maintain suspension working space level within design limit and to minimize body acceleration level. The results showed that the four setting switchable damper gives better ride improvements compared with the two and three setting switchable dampers.
2016-04-05
Technical Paper
2016-01-0443
Han Zhang, Gang Li, Yu Wang, Yuchuan Gu, Xiang Wang, Xuexun Guo
Abstract A vehicular hydraulic electrical energy regenerative semi-active suspension(HEERSS) was presented, and its working principle and performance were analyzed. Firstly, configuration and working principle of the HEERSS were described; Secondly, kinetic equation of HEERSS was deduced, and a skyhook controller was designed for HEERSS. The traditional skyhook control strategy should be changed for the characteristic of HEERSS, because the damping force during extension stroke could be controlled, but not in compression stroke. Thirdly, the performance of HEERSS was compared with passive suspension(PS), traditional semi-active suspension(TSS). The simulation results indicated that the performance of HEERSS would be compromise between TSS and PS, but the HEERSS could harvest vibration energy which was advanced than TSS and PS.
2016-04-05
Technical Paper
2016-01-0442
Xing Xu, Zou Nannan
Interconnected air suspension system can change a vehicle’s operation characteristics by exchanging gas between air springs. In this paper, we analyze the structure and working principle of interconnected air suspension based on thermodynamics and vehicle dynamics. Then air suspension’s mathematical model including interconnected characteristics is established to study gas exchange principle of air suspension system. Interconnected pipeline parameters and excitation phase differences’ influence on characteristics of air suspension system in whole vehicle are calculated and analyzed. Simulation results show that the stiffness of air suspension is reduced when air springs of the suspension system are interconnected, as well as it decreases gradually with the increase of interconnected pipeline diameter; the stiffness of air springs is minimum if the excitation phase difference between both sides of air springs is 180 degrees.
2016-04-05
Technical Paper
2016-01-0428
Ruochen Wang, Renkai Ding, Qing Ye
Abstract For coordinating the ride comfort and driving safety, the “inerter-spring-damper” (ISD) system is proposed in this paper, and the “spring-adjustable damper” is adapted to connect with ISD in series, then, a new type of semi-active suspension system is established. In order to verify the system rationality, the ISD semi-active suspension model and robust controller model are established respectively in the AMESim and MATLAB/Simulink environment, which is based on two degrees of freedom suspension model. Then, the co-simulation of ISD semi-active suspension with robust control is analyzed. Compared with the conventional ISD suspension, the results show that, the ISD semi-active suspension with robust control can significantly reduce the body vertical vibration, restrain tire resonance and enhance the tire grounding, that is, this system can coordinate the conflicts between vehicle ride comfort and driving safety.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
Abstract The performance of a structural design significantly depends upon the assumptions made on input load. In order to estimate the input load, during the design and development stage of the suspension assembly of a BAJA car, designers and analysts invest immense amount of time and effort to formulate the mathematical model of the design. These theoretical formulations may include idealization errors which can affect the performance of the car as a final product. Due to the errors associated with the assumption of design load, several components might have more weight or may have less strength than needed. This discrepancy between the assumed input load (lab or theoretical studies) and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to give engineers insight to understanding the complex real world loading of their structures.
2016-04-05
Technical Paper
2016-01-0431
Guangqiang Wu, Huwei Wu, Xiang Chen
Abstract The nonlinear characteristics impact of multi-staged stiffness clutch damper on the vehicle creeping is investigated by using the lumped-parameter modeling method as a certain mass-production passenger sedan is taken as the research subject. Firstly, a quasi-transient engine model of an inline four-cylinder and four-stroke engine, based on measured data of cylinder gas pressure versus crankshaft angle, is derived. Effective output torque is acquired and as the input excitation to the driveline system. Secondly, a 12-DOF (Degree of Freedom) nonlinear and branched powertrain system and vehicle longitudinal dynamics model is established. The differential mechanism characteristics and dynamic tire property based on the LuGre tire model are considered. Then, for a traditional two-staged stiffness clutch damper in consideration of hysteresis characteristics, vehicle powertrain system responses in both the time and frequency domain are obtained.
2016-04-05
Technical Paper
2016-01-0430
Joel Metz, Xin Zhang, Xiao Yu
The Front Lower Control Arm (FLCA) is a key part of the automotive suspension for performance and safety. Many FLCA designs attach to the front sub-frame using rubber handling and riding bushings, which determine the vehicle dynamics and comfort. In this paper, a design for a ride bushing using a metal pin structure is discussed. The inner portion of the ride bushing is a hollow metal collar with a layer of rubber, and the FLCA pin structure is pressed into the rubber. For safety requirements, the bushings must meet a pin push-in and push-out force requirement. During the development of the bushing design, different test groups conducted tests to determine if manufactured parts meet the push-out force specification. Each group tested at a different load rate and generated different maximum push out force values. The push-in/out speed was found to have a strong influence on the generated maximum load.
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
2016-01-0471
Jian Zhao, Jun Huang, Bing Zhu, Jingwei Shan
In the past decades, the stability of vehicles has been improved significantly by use of variety of chassis control systems such as Antilock Braking System (ABS), Electric Stability Program (ESP) and Active Front Steering (AFS). Recently, in order to further improve the performance of vehicles, more and more researches are focused on the integration control of multiple degrees of freedom of vehicle dynamic. However, in order to control multiple degrees of freedom simultaneously, the nonlinear problems caused by the coupling between different degrees of freedom have to be solved, which is always a difficult task. In this paper, a three-degrees-of-freedom single track vehicle model, in which some nonlinear terms are considered, is built firstly. Then, the nonlinear model is processed by the fuzzy technique and the T-S fuzzy model is designed.
2016-04-05
Technical Paper
2016-01-0470
Wei Chen, Zhe Sun, Jun Zheng, Liang Pan, Xurong Yi
Abstract This paper presents the relationship between suspension and steering systems and wheels, and proposes the vehicle dynamics modeling method. A vehicle dynamics model combined with the suspension K&C test data of a concrete vehicle was built based on the method. The simulation results show that the method is correct and feasible, and the dynamics model performed characteristics of the suspension and steering systems with high precision can be used for the followup simulation and optimization.
2016-04-05
Technical Paper
2016-01-0469
Hyunkoo Kang, Wooyong Jung, Choon Lee
Abstract This paper presents payload estimation based on experimental friction coefficients identification. To estimate exact payload mass, dynamic mathematical model such as actuator dynamics and front linkage dynamics is derived by using Newton-Euler method. From the dynamic equation, nonlinear terms are analyzed and transformed. And a friction model is derived from the experiments with various conditions which have three states; boom joint angle, head and rod chamber pressures. It can identify friction coefficients and compensate friction forces. In addition, the accuracy of payload estimation system is verified through the field test.
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
2016-01-0460
Salem A. Haggag, Abraham Mansouri
Abstract The control of automotive braking systems performance and wheel slip is a challenging problem due to the nonlinear of the braking process, vehicle body dynamics during braking and the tire-road interaction. When the wheel slip is not between the optimal limits during braking, the desired tire-friction force cannot be achieved, which influences the braking distance, the loss in steerability and maneuverability of the vehicle. A simple and at the same time realistic vehicle longitudinal braking model is essential for such challenging problem. In this paper, a new longitudinal rolling/braking lumped-vehicle model that takes vehicle aerodynamic forces in consideration is presented. The proposed model takes the rolling resistance force, the braking force and the aerodynamic lift and drag forces in consideration and investigates their impact on the vehicle longitudinal dynamics especially vehicle braking distance and time.
2016-04-05
Technical Paper
2016-01-0518
Choonsoo Han
Abstract Thermoplastic polyester elastomer (TPEE) has the properties of both rubber and engineering plastic. The most important characteristics of this material are its high elasticity and rigidity. So, those properties are enable to high durability against fatigue and large deformation cycles. In this study, the rebound bumper of suspension system in vehicle, using thermoplastic polyester elastomer was conducted. The plastic elastomer rebound bumper allows cost reduction and light weight on by integrating several components, such as coil spring, spring guides, blocker, stop rubber etc. In order to satisfy several component requirements such as specific compression set and Load-Displacement curve etc, we evaluated the performance change according to the design and material of the component. This study shows that how to modify the design of the rebound bumper to meet the requirments, and to choose the optimum material through the verification comparing several materials.
2016-04-05
Technical Paper
2016-01-0508
Hyung Seok KIM
Abstract This study provides a tire puncture sealant including NR latex and acrylic emersion, which has a reduced viscosity at -40°C, and is also excellent storage stability at -40°C to 70°C, initial sealing performance. Also, this study provides device for sealing inflatable objects. 'One- Piece Tire Repair Kit' can reduce weight and operation steps.
2016-04-05
Technical Paper
2016-01-0507
Kazunori Miyake, Tomoya Nishida, Takanori Kurokawa, Hirokazu Arai
Abstract Sliding intermediate shaft of Electric Power Steering (EPS) system is used for torque transmission from steering wheel or motor and buffering reverse input from tire. Polyamide coating material with good sliding properties is treated in the sliding types of intermediate shaft. Conventionally, sliding types of intermediate shaft with polyamide coating have been used in vehicle interior. On the other hand, extension of applied area to engine room is needed. However, in high temperature conditions, there is concerns about increase of friction coefficient and wear volume of polyamide by deterioration of sliding properties of polyamide. Therefore, improvement of sliding properties of polyamide in high temperature is necessary. In this research, we examined sliding properties of polyamide blended with metal stearate in high-temperature to use polyamide in high temperature compared to conventional environment. As resin material, we used polyamide 610 blended with metal stearates.
2016-04-05
Technical Paper
2016-01-1075
Jonathan Plail, Petr Grinac, Helen Ballard
Abstract In this paper, a mathematical model for simulating the 3D dynamic response of a valve spring is described. The 3D model employs a ‘geometrically exact’ 3D beam connected between each mass of the discretised mass-elastic system. Shear deformations within the beam are also considered, which makes it a Timoshenko type finite element. Results from the 3D model are compared with results from a more conventional 1D model. To validate the results further, some results are compared with real test data that was gathered during a technical consulting project. In this project, a prototype valvetrain that was originally giving acceptable durability began to wear the spring seats when a new batch of springs were procured and tested. 1D and 3D simulation results were used to help understand the cause of the failure and to make recommendations to resolve the issue. Results showed that the 3D model was able to predict the spring seat loads with greater precision than the 1D spring could.
2016-04-05
Technical Paper
2016-01-1555
Jack Ekchian, William Graves, Zackary Anderson, Marco Giovanardi, Olivia Godwin, Janna Kaplan, Joel Ventura, James R. Lackner, Paul DiZio
Abstract It is widely anticipated that autonomous vehicles will offer increased productivity and convenience by freeing occupants from the responsibility of driving. However, studies indicate that the occurrence of motion sickness in autonomous vehicles will be substantially higher than in conventionally driven vehicles. Occupants of autonomous vehicles are more likely to be involved in performing tasks and activities, such as reading, writing and using a computer or tablet, that typically increase the occurrence of motion sickness. The authors present a novel high bandwidth active suspension system, GenShock®, and tailored control algorithms targeted toward mitigating motion sickness in autonomous vehicles. GenShock actuators can actively push and pull the wheels of a vehicle in order to keep the chassis level and reduce heave, pitch, and roll motion.
2016-04-05
Journal Article
2016-01-1568
L. Daniel Metz
Abstract Roadway tractive capabilities are an important factor in accident reconstruction. In the absence of full-scale experiments, tire/road coefficient of friction values are sometimes quoted from reference textbooks. For the various types of road construction, the values are given only in the form of a wide range. One common roadway type is oil-and-chip construction. We examine stopping distances for newly-rocked oil-and-chip roads vs. similarly constructed roads that have been traffic-polished. The examination was conducted through full-scale braking experiments with instrumented vehicles. Results show that the differences between newly-rocked oil-and-chip roads when compared to roads that are traffic-polished are on the same order as vehicle, tire and ABS algorithm differences, and that full-scale testing is required for accurate μ-values.
2016-04-05
Journal Article
2016-01-1553
Akihito Yamamoto, Wataru Tanaka, Takafumi Makino, Shunya Tanaka, Ken Tahara
Abstract This paper reports that estimation accuracy of suspension stroke velocity is increased by considering the damping force delay characteristics to an observer. Thereby ride comfort is improved, using the simple and low-cost semi active suspension systems that use only three vertical acceleration sensors.
2016-04-05
Journal Article
2016-01-1572
Jugal Popat, Aneesh Nabar, Meighan Read, Chen Fu, Chunhui Zhang, Galab Kausik, Harsh Patel, Peter Thomas Tkacik
Abstract Published information on studies of something so critical to safety as passenger vehicle tire pressures can be found [1, 2]; however, they only account for rolling tires. Studies related to spare tire pressures are lacking. This paper is the result of measurements on 150+ vehicles and the most surprising results are presented regarding the influence of Tire Pressure Monitoring Systems (TPMS) and the new spare tire locations and use. A statistical study was performed on the collected data to determine the correlation between tire pressures, vehicle age and TPMS. One particular topic of investigation was the relationship between various factors that influence spare tire pressure. Some newer models, particularly some mini-vans, have placed the spare tire in an unusual and inconvenient place for regular maintenance. Based on the data collected, TPMS has a positive influence on rolling tires but not on spare tires.
2016-04-05
Journal Article
2016-01-1571
Harsh Patel, Michael Casino, David Noakes, Nicholas Kauffman, Daniel Rohwedder, Jugal Popat, Aneesh Nabar, Peter Thomas Tkacik
Abstract This paper is part of a bigger research effort that aims to capture the influences of static wheel alignment measurement accuracy for road going vehicles. Vehicle alignments can and often are the bottleneck in automotive and truck assembly lines and a greater understanding of the issues are very valuable. The alignment equipment in this research has been tuned and adjusted to minimize external variables and the team of authors have 300+ vehicle measurements. Of the many things that influence the accuracy and repeatability of vehicle suspension alignment measurement and adjustment, the measurement procedures can be the most significant. This includes but is not limited to alignment machine setup and vehicle tire pressures.
2016-04-05
Journal Article
2016-01-1569
Kiho Yum
Abstract In this research, the influence of tire force and moment (F&M) characteristics on vehicle on-center steering performance was analyzed and then how to improve vehicle on-center performance was studied through controlling tire structure design parameter, tread pattern shape and tread grip characteristics. First, the relationship between vehicle on-center steering performance and tire F&M characteristics was identified by comparing vehicle steering measurements and tire F&M measurements. It was found that key factor of tire related with on-center performance is aligning torque at lower slip angles. As the aligning torque at slip angle 1° increases, on-center feel is improved. Second, the influence of tire design parameters on tire aligning torque was studied through F&M finite element (FE) analysis and measurement. It was found that the aligning torque at lower slip angle increases as stiffness of the tread and sidewall decreases.
2016-04-05
Journal Article
2016-01-1630
Benjamin Hirche, Beshah Ayalew
In this paper, a soft computing approach to a model-free vehicle stability control (VSC) algorithm is presented. The objective is to create a fuzzy inference system (FIS) that is robust enough to operate in a multitude of vehicle conditions (load, tire wear, alignment), and road conditions while at the same time providing optimal vehicle stability by detecting and minimizing loss of traction. In this approach, an adaptive neuro-fuzzy inference system (ANFIS) is generated using previously collected data to train and optimize the performance of the fuzzy logic VSC algorithm. This paper outlines the FIS detection algorithm and its benefits over a model-based approach. The performance of the FIS-based VSC is evaluated via a co-simulation of MATLAB/Simulink and CarSim model of the vehicle under various road and load conditions. The results showed that the proposed algorithm is capable of accurately indicating unstable vehicle behavior for two different types of vehicles (SUV and Sedan).
2016-04-05
Journal Article
2016-01-1637
Hongyuan Zang, Zhuoping Yu, Lu Xiong
Abstract To analyze the K&C (kinematics and compliance), handling and stability performance of the vehicle chassis, some simulations are usually performed using a multi-body dynamics software named ADAMS. This software introduces assumptions that simplify the components of the suspension as rigid bodies. However, these assumptions weaken the accuracy of the simulation of ADAMS. Therefore the use of flexible bodies in K&C and handling and stability simulation in ADAMS is needed to conduct more precise suspension system designs. This paper mainly analyses the influences of the subframe flexibility on handling and stability simulation in ADAMS/Car. Two complete vehicle models are built using ADAMS/Car and Hypermesh. The only difference between the two models is the subframe of the front McPherson suspension. One of the subframes is simplified as a rigid body. The other one is a flexible body built using the MNF file from Hypermesh.
2016-04-05
Journal Article
2016-01-1635
Donald F. Tandy, Jung Bae, Jason Colborn, Clay Coleman
Abstract Recreational Off Road Vehicles (ROVs) which are sometimes referred to as side-by-sides, have increased in popularity over the last decade. These vehicles are available in many different sizes and performance characteristics from a host of different manufacturers and also have a variety of different missions, just as there are many types of off road terrain. The United States Federal Government, through the Consumer Product Safety Commission (CPSC), has advocated and proposed vehicle handling and rollover resistance standards for the side-by-sides which have a top speed above 25 miles per hour (these are not defined as “low speed vehicles”). For the sake of repeatability, the proposed maneuvers are to be performed on a high friction hard surface (like asphalt) as opposed to the off road surfaces (i.e. grass, sand, dirt, mud. rocks, etc.) that these vehicles are designed to be operated on.
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