Display:

Results

Viewing 151 to 135 of 135
2015-04-14
Journal Article
2015-01-0651
Mustafa Ali Arat, Saied Taheri, Edward Holweg
The road profile has been shown to have significant effects on various vehicle conditions including ride, handling, fatigue or even energy efficiency; as a result it has become a variable of interest in the design and control of numerous vehicle parts. In this study, an integrated state estimation algorithm is proposed that can provide continuous information on road elevation and profile variations, primarily to be used in active suspension controls. A novel tire instrumentation technology (smart tire) is adopted together with a sensor couple of wheel attached accelerometer and suspension deflection sensor as observer inputs. The algorithm utilizes an adaptive Kalman filter (AKF) structure that provides the sprung and unsprung mass displacements to a sliding-mode differentiator, which then yields to the estimation of road elevations and the corresponding road profile along with the quarter car states.
2015-04-14
Journal Article
2015-01-0649
Liangyao Yu, Shuhao Huo, WenWei Xuan, Lei Zuo
Abstract Conventional viscous shock absorbers, in parallel with suspension springs, passively dissipate the excitation energy from road irregularity into heat waste, to reduce the transferred vibration which causes the discomfort of passengers. Energy-harvesting shock absorbers, which have the potential of conversion of kinetic energy into electric power, have been proposed as semi-active suspension to achieve better balance between the energy consumption and suspension performance. Because of the high energy density of the rotary shock absorber, a rotational energy-harvesting shock absorber with mechanical motion rectifier (MMR) is used in this paper. This paper presents the assessment of vehicle dynamic performance with the proposed energy-harvesting shock absorber in braking process. Moreover, a PI controller is proposed to attenuate the negative effect due to the pitch motion.
2015-04-14
Journal Article
2015-01-0656
Amir Soltani, Francis Assadian
Abstract A new control strategy for wheel slip control, considering the complete dynamics of the electro-hydraulic brake (EHB) system, is developed and experimentally validated in Cranfield University's HiL system. The control system is based on closed loop shaping Youla-parameterization method. The plant model is linearized about the nominal operating point, a Youla parameter is defined for all stabilizing feedback controller and control performance is achieved by employing closed loop shaping technique. The stability and performance of the controller are investigated in frequency and time domain, and verified by experiments using real EHB smart actuator fitted into the HiL system with driver in the loop.
2015-04-14
Journal Article
2015-01-0655
Francesco Calabrese, Manfred Baecker, Carlos Galbally, Axel Gallrein
Abstract Currently used tire models have shown a certain lack of accuracy in some advanced handling applications. This lack of accuracy is believed to be partly due to thermal effects. In reality, the tire rubber temperature is not constant during the normal operating conditions and it's really well known that the tire friction coefficient strongly depends on the temperature level. The temperature generation, propagation and evolution are the result of a dynamic energy equilibrium between phenomena of different natures. Various mechanisms create a non-uniform temperature distribution in various parts of the tire structure: heat is generated in zones with large cyclic deformations due to the energy dissipated from the rubber strains and in the sliding part of the contact patch due to friction. The rubber cools down because the heat energy transferred to the air (internally and externally) and to the asphalt in the stick zone of the contact patch.
2015-04-14
Journal Article
2015-01-0665
Yongchang Du, Yujian Wang, Pu Gao, Yingping Lv
Abstract Modelling of disc in brake squeal analysis is complicated because of the rotation of disc and the sliding contact between disc and pads. Many analytical or analytical numerical combined modeling methods have been developed considering the disc brake vibration and squeal as a moving load problem. Yet in the most common used complex eigenvalue analysis method, the moving load nature normally has been ignored. In this paper, a new modelling method for rotating disc from the point of view of modal is presented. First finite element model of stationary disc is built and modal parameters are calculated. Then the dynamic response of rotating disc which is excited and observed at spatial fixed positions is studied. The frequency response function is derived through space and time transformations. The equivalent modal parameter is extracted and expressed as the function of rotation speed and original stationary status modal parameters.
2015-04-14
Journal Article
2015-01-0668
Yongchang Du, Pu Gao, Yujian Wang, Yingping Lv
Abstract The study and prevention of unstable vibration is a challenging task for vehicle industry. Improving predicting accuracy of braking squeal model is of great concern. Closed-loop coupling disc brake model is widely used in complex eigenvalue analysis and further analysis. The coupling stiffness of disc rotor and pads is one of the most important parameters in the model. But in most studies the stiffness is calculated by simple static force-deformation simulation. In this paper, a closed-loop coupling disc brake model is built. Initial values of coupling stiffness are estimated from static calculation. Experiment modal analysis of stationary disc brake system with brake line pressure and brake torques applied is conducted. Then an optimization process is initiated to minimize the differences between modal frequencies predicted by the stationary model and those from test. Thus model parameters more close to reality are found.
2015-04-14
Journal Article
2015-01-0667
Kei Ichikawa
Abstract Cabin quietness is one of the important factors for product marketability. In particular, the importance of reducing road noise is increasing in recent years. Methods that reduce acoustic sensitivity as well as those that reduce the force transferred from the suspension to the body (the suspension transfer force) are used as means of reducing road noise. Reduction of the compliance of the body suspension mounting points has been widely used as a method of reducing acoustic sensitivity. However, there were cases where even though this method reduced acoustic sensitivity, road noise did not decrease. This mechanism remained unclear. This study focused on the suspension transfer force and analyzed this mechanism of change using the transfer function synthesis method. The results showed that the balance between the body's suspension mounting points, suspension bush, and suspension arm-tip compliance is an important factor influencing the change in suspension transfer force.
2015-04-14
Journal Article
2015-01-1309
Hyunggyung Kim
Abstract This Study describes about the development of new concept' rear wheel guards for the reduction of Road Noise in the passenger vehicles. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance and vehicle tests. Through new developing process without vehicle test, Result of road noise will be expected if this concepts and materials of wheel guard are applied into automotive vehicle. As this concept consider tire radiation noise frequency and multilayers sound control multilayers, 2 concepts reduced road noise from 0.5 to 1.0dB. The proposed method of part reverberant absorption is similar to results of vehicle tests by part absorption index. Furthermore, optimization of frequency band in wheel guards will reduce more 0.5 dB noises.
2015-04-14
Journal Article
2015-01-1314
Max Sardou, Patricia Djomseu
Abstract SARDOU SAS has developed highly stressed composites parts for 35 years. SARDOU SAS and QUALITY INDUSTRIAL PRODUCT invented composite coils springs in 2002. Developing composite coils springs, we have faced a big challenge, how to increase the short life expectancy of this highly stressed structure? We have identified that the weak point, in composite coils springs, is its epoxy matrix. In fact, during heavy loading, the matrix undergoes micro cracks. Then, during fatigue, micro cracks propagate and merge, transforming the matrix into a fine powder. The composite coil suspension springs, using, classic epoxy, where ruined after only 100,000 cycles in the best cases. The fact to integrate “functionalized silica aggregates”, in the matrix, enable the springs to exceed 1,000,000 cycles, with the same spring design. In addition, the spring stiffness has increased by 6% and the thermal set has reduced by 1.6%.
2015-04-14
Journal Article
2015-01-1505
Ibrahim A. Badiru
Abstract Vehicle steering wheel pull is a condition experienced by customers where a constant torque at the steering wheel is required to maintain a straight path. Steering wheel pull may be accompanied by the secondary effects of steering wheel angle misalignment and vehicle thrust angle “dog-tracking.” EPS pull compensation is a feature that can automatically compensate vehicle steering wheel pull. This paper examines customer benefits, operating principles, effectiveness, and robustness of EPS pull compensation in vehicles. Vehicle road test data indicate EPS can correct a severe vehicle steering wheel pull. Using fundamental physics equations, an analysis tool is derived to support further investigation of steering wheel angle misalignment and vehicle thrust angle. The final section presents a designed experiment revealing parameters most influencing vehicle robustness to chassis and road characteristics.
2015-04-13
Article
The basic concept of the tire hasn’t changed since stone rollers used to help build the pyramids--it’s the way we make them and the design that has changed, says Ydo Doornbos of Trelleborg Wheel Systems Americas.
2015-04-10
Standard
J3081_201504
This document is written to address acceleration and deceleration control issues related to Heavy Duty Trucks and Buses greater than 10 000 GVW.
2015-04-08
WIP Standard
ARP1907C
This Aerospace Recommended Practice (ARP) covers the functional, design, construction, and test requirements for Automatic Braking Systems. Installation information and lessons learned are also included.
2015-04-07
Article
The new Spicer AdvanTEK tandem axle concept is optimized for trucks that implement engine “downspeeding,” combining the traction offered by a 6x4 configuration with the reduced drivetrain losses of a 6x2.
2015-03-30
Technical Paper
2015-01-0101
Piyapong Premvaranon, Jenwit Soparat, Apichart Teralapsuwan, Wuttipong Sritham, Chi-na Benyajati, Nathapol Taweewong
Abstract Due to recent oil price crisis and an ever-increasing public awareness on environmental issues, an interest in electric vehicles (EV) has increased tremendously in Thailand and other Asian countries over the last few years. In this study, a prototype of 9-metre battery electric vehicle (BEV) bus was chosen as a vehicle of interest to undergo a series of field test by operating the lead acid battery powered electric bus in order to estimate a power demand of the bus as well as to evaluate a battery performance characteristic Two different types of battery were employed in this study i.e. a flooded-type deep cycle lead acid battery and a valve regulated lead acid (VRLA) battery. The effect of different driving modes available from the drive motor i.e. normal, max power, max range, as well as regenerative braking feature would be investigated while an influence of drivers were also taken into account to ensure the repeatability of the obtained results.
2015-03-30
Technical Paper
2015-01-0090
Cherdsak Chuaymung, Chi-na Benyajati, Sutee Olarnrithinun
Abstract A vehicle of interest in this paper was a light agriculture truck. In order to obtain reliable predictions of stress generated in the frame under loads, a combination of experimental tests and computer simulations was arranged. Since the focused deformations were bending and torsion modes, the truck driven up one-wheel ramp and two-wheel ramp was investigated. Strains results obtained from both tests and simulations were compared. The discussions and conclusions were made regarding the accuracy and further improvements of the simulations.
2015-03-30
Technical Paper
2015-01-0081
Hsin Guan, Chunguang Duan, Pingping Lu, Jun Zhan, Yunting He
Abstract With the development of computer and vehicle research to high frequency, the driving simulator plays an important role on vehicle research and pre-development. The driving simulator have already been used for research about human factors, advanced active system (ABS, ESP et al), the vehicle dynamics and intelligent transportation systems (ITS) et al. The crucial requirement for a driving simulator is that it should have realistic behavior. The realistic behavior base on high-fidelity dynamics models especially tire model. “Tire/road” model is of special importance model for its influence on vehicle performances. The forces for accelerating, braking and steering are all came from tire road contact. The simulator simulation faces all possible driving scenes as driving in the real word, like parking on the hill, stop and start again, sharp steering and sharp braking et al.
2015-03-30
Technical Paper
2015-01-0082
Husain Kanchwala, Carlos Bordons
Abstract Electric vehicles (EVs) have been gaining a lot of focus and attention as they run clean and are environment friendly. EVs use in-hub motors, which can be independently controlled, improving this way the maneuverability and allowing augmented control actions. This paper discusses the development of a Model Predictive Controller (MPC) to improve vehicle handling characteristics. Wheel torques are independently controlled using direct yaw moment and side slip control method to pro-actively improve vehicle handling. At high values of side slip the steering is no more capable of generating yaw moment and vehicle becomes laterally unstable. By unequal torque distribution a restoring yaw moment is generated and vehicle stability is ensured. The MPC computes the optimal couple traction/braking torque of the four in-wheel motors, from basic driving slogans, which are, steering angle and desired speed.
2015-03-25
Magazine
Bringing it all together Ian Adcock catches up with GKN's newly appointed president, Group Technology, Rob Rickell. Graphene Supreme Ian Adcock discovers what role graphene is likely to play in the vehicles of tomorrow. What lies beneath? Automotive Design looks into chassis developments that are designed to ensure local preferences are catered for globally.
2015-03-23
Article
The company has expanded its additive manufacturing material capabilities to support metal 3-D printing of complex high-hardness parts and the ability to customize properties layer-by-layer through “gradient material design.”
2015-03-19
Standard
J2633_201503
This SAE lab test procedure should be used when performing the following specialized weathering tests for wheels; Florida Exposure, QUV, Xenon and Carbon Weatherometer. In addition to these procedures, some additional post-weathering tests may be specified. Please refer to customer specifications for these requirements.
2015-03-19
Standard
J2634_201503
This SAE practice is intended for the sample preparation of test pieces for automotive wheels and wheel trim. The practice provides a consistent scribing method for use on test panels and or component parts with substrate chemical pretreatment and coating systems. Test specimens can then be subjected to various corrosion tests in order to evaluate performance without significant variations of the degree of exposure of the substrate. The scribing is used to create a break in the coating/finishing as can occur in the field through gravel and other damaging conditions. Significant variability is attributed to surface contour, coating hardness/softness, operator reproducibility, and the scribing tool and it's condition.
2015-03-13
Standard
J1965_201503
This SAE Recommended Practice applies to fasteners/fixing nuts as specified in SAE J694 and SAE J1835 used for disc wheels and demountable rim attachment respectively. Only the test methods necessary to assure proper wheel or rim assembly are specified. Fasteners for less common and special applications are not included.
2015-03-11
Article
Novel aluminum-rich steel alloy could find structural use in road vehicles and even aircraft.
2015-03-10
Technical Paper
2015-01-0016
Changxin Wang, Wenku Shi, Zan Li, Fuxiang Guo
Abstract This paper presents the study of chassis tuning of a commercial vehicle, which has a rear suspension with dual stage leaf spring assembly and a front suspension with double wishbone torsion bar. To balance the handling and ride performance of the vehicle, it is necessary to tune the key suspension parameters of the chassis including the dual stage stiffness of the leaf spring, the contact load of the leaf spring, the torsional rigidity of the torsion bar, the force curve of the front and rear dampers etc. The chassis tuning process of a physical commercial vehicle was first put forward. In the proposed flowchart, the kinematics and statics of front & rear suspensions were checked at the beginning of the tuning. Then the tire mechanical characteristics were tested by using a plate-type tire tester and the inertial parameters of the vehicle were indirectly measured. The K&C characteristics of front and rear suspensions were also tested and compared with the benchmark vehicle's.
2015-03-10
Technical Paper
2015-01-0017
Yufeng Wang, Zhizhong Wang, Liangyao Yu, Jian Song
Abstract Many types of brake by wire systems have been developed in past years, such as EMB (Electro-mechanical Brake) [1, 2], DEHB (Distributed Electro-hydraulic Braking System) [3] and EWB (Electric Wedge Brake) [4]. When the vehicle need braking in long period such as waiting for traffic light or downhill braking in those brake systems, the current will sustain very long time with very high level. This current will result in high temperature in motor, and will damage the power supplier. When a new DEHB is developing, a holding function is added in this DEHB. The holding function is self-energized when holding the brake, and automatic released after the brake. Advantageously, after activation of the holding function, the current delivered to the motor for braking is substantially decreased, especially, will be zero when the brake torque is not need to adjust.
2015-03-10
Technical Paper
2015-01-0025
Jaeyong Park, Joonhong Park, JinHee Lee, Yong-Sub Yi, TeaWon Park
Abstract In the view point of driving safety, the crosswind sensitivity of a vehicle becomes more important, as the driving speed in highway gets higher in these days. The sensitivity of a vehicle to crosswind depends on many factors, including the design of the suspension and aerodynamics of the body, etc. However, the knowledge about this phenomenon has still to be improved, in order to develop vehicle with optimum characteristics for crosswind stability. In this research, the physics behind the sensitivity of a vehicle is discussed in detail through various kinds of virtual test using computer aided engineering (CAE) simulation scheme. In the first, a reliable simulation model for vehicle, driver, wind generator and interactions among them is built. This simulation model is verified by comparison with test results of real vehicle. Then, the sensitivity analysis is carried out to find out the most influential design parameters.
2015-03-10
Technical Paper
2015-01-0026
Wenku Shi, Changxin Wang, Zan Li
Abstract In order to improve the handling and stability of a light bus at high speed, a virtual model was established in Adams-Car and its anti-roll bar and bushing parameters were virtually optimized. The tyre mechanical characteristics were firstly tested by using a plate-type tyre tester and the Magic Formula parameters of the tyre were obtained. Then the virtual bus model's handling performance were studied by the simulation of central steering test and steady static circular test. An optimal matching method was put forward. By using genetic algorithm to conduct optimization, the optimised parameters were obtained. After that the anti-roll bar and bushing samples were respectively manufactured. At last, the comparative trials were performed in an automotive proving ground, and the subjective evaluation of the light bus's handling and stability was taken by three specialized assessors.
2015-03-10
Technical Paper
2015-01-0021
Lauri Ohra-aho, Joshua Chan, Walter My
Abstract Computer aided engineering (CAE) methods have been part of Electronic Stability Control (ESC) system development since its introduction to the market in 1995, especially in the testing and verification phase. Over time, additional CAE tools and methods have been introduced, ranging from small self-learning algorithms to automatic tuning tools for individual functions. Since the end of 2009, ECE regulations have allowed the use of CAE methods for ESC homologation, and in North America, the exemption from FMVSS126 compliance for aftermarket parts was phased out in 2012. Following these legislative changes, several original equipment manufacturers, aftermarket companies and ESC suppliers are using vehicle dynamics computer simulation methods to predict ESC performance and homologate vehicles.
2015-03-10
Technical Paper
2015-01-0042
Changxin Wang, Wenku Shi, Yiming Wang, Teng Shi
Abstract This paper presented one calculation method of the contact load, which is the load acted on the spring at the moment when the second-level stiffness of the spring just begins to work. In the proposed method, the contact load calculation mainly based on the dynamic load of the unsprung mass and the road grades and the commonly driving speed were also considered. A semiempirical formula of the contact load was put forward. Then the contact load of the commercial bus's rear suspension was respectively calculated by using the proposed formula and traditional methods(geometric mean method and average load method) to compare each other and to verify the new method. Later, the spring samples were respectively manufactured based on the calculation results. At last, the validation tests were respectively performed in an automotive proving ground.
Viewing 151 to 135 of 135

Filter