Criteria

Text:
Display:

Results

Viewing 1 to 30 of 2648
2016-04-05
Technical Paper
2016-01-1347
S. Khodaygan
Fixtures play a key role in locating workpieces to manufacture high quality products within many processes of the product lifecycle. Inaccuracies in workpiece location lead to errors in position and orientation of machined features on the workpiece, and strongly affect the assemblability and the final quality of the product. The accurate positioning of workpiece on a fixture is influenced by rigid body displacements and rotations of the workpiece. In this paper, a systematic approach is introduced to investigate the located workpiece position errors. A new mathematical formulation of fixture locators modeling is proposed to establish the relationship between the workpiece position error and its sources. Based on the proposed method, the final locating errors of the workpiece can be accurately estimated by relating them to the specific dimensional and geometric errors or tolerances of the workpiece and the related locators.
2016-04-05
Technical Paper
2016-01-0079
Tomohisa Harada, Yoshiyuki Hattori, Shinya Ito, Mitoshi Fujimoto, Toshikazu Hori
Recently, the electromagnetic interference to an AM radio by the noise generated from a power control unit in an HV has become a serious problem. In order to solve the problem, most of noise countermeasures focus on noise sources and noise propagation paths. On the other hand, a countermeasure in the radio receiver has been also proposed. This method detects the HV noise by using a noise sensor, and then, the noise signal is subtracted from AM radio signal which the noise superimposed. In this paper, a new noise suppression method using the digital signal processing in the AM radio receiver is proposed, which does not need noise sensors. The procedure of the method is as follows: First, a receiving AM radio signal containing HV noises is resolved into the in-phase component and quadrature component of a carrier by applying a quadrature demodulation.
2016-04-05
Technical Paper
2016-01-1536
Chung-Kyu Park, Cing-Dao Kan
The vehicle crash pulse severity is a measure of how severely the vehicle crash pulse has an effect on the occupant injury. The objective of this research is to evaluate the assessability of vehicle crash pulse severity in frontal New Car Assessment Program (NCAP) tests. In this study, the existing metrics derived from vehicle crash pulse in the frontal impact are reviewed and categorized into 4 groups in the way of how occupant responses are considered. Then the severity of vehicle crash pulses of the frontal NCAP tests was evaluated by existing metrics. A total of 60 frontal NCAP test data collected from the MY 2012 vehicle test program are analyzed. The linear regression analyses and sled test simulations are conducted to identify their correlation to other metrics and dummy injuries. The results show that some of existing metrics are able to assess crash pulse severity in frontal NCAP tests.
2016-04-05
Technical Paper
2016-01-0984
Venkatraman Mahadevan, Suresh Iyer, David Klinikowski
This paper investigates the effect of time alignment in the calculation of emissions from the raw exhaust stream of heavy-duty vehicles when tested on a chassis dynamometer. The effect of time alignment is significant in this case, as time-variant raw exhaust flow rate and emissions concentrations data are acquired continuously during a test (at 10 Hz), and their product is integrated during calculations. The response of the analyzer is delayed due to the time taken for transportation of the sample gases from the probe tip to the analyzer, and ‘flattened’ due to diffusion during this transport. This ‘convolution’ of the concentration data stream introduces an error in the final result, calculated in grams/mile. The convolution of the concentration data is corrected by the following method: the analyzer response (output) to a step change in the concentration of the species at the probe tip (input) is recorded to determine the ‘convolution function’.
2016-04-05
Technical Paper
2016-01-1448
Rong Chen, Rini Sherony, Hampton C. Gabler
The effectiveness of Forward Collision Warning (FCW) or similar crash warning/mitigation systems is highly dependent on driver acceptance. If a FCW system delivers the warning too early, it may distract the driver or annoy the driver and cause him/her to deactivate the system. In order to design a system activation threshold that matches driver expectations, system designers must understand when drivers would normally apply the brake. One of the most widely used metrics to establish FCW threshold is Time to Collision (TTC). TTC measures the time remaining before two vehicle would collide if they continued at their current speeds. One limitation of TTC is that it assumes constant vehicle velocity. Enhanced Time to Collision (ETTC) is potentially a more accurate metric of perceived collision risk due to its consideration of vehicle acceleration. This paper will compare and contrast the population distribution of ETTC and TTC at brake onset in normal car-following situations.
2016-04-05
Technical Paper
2016-01-0471
Jian Zhao, Jun Huang, Bing Zhu, Jingwei Shan
As the vehicle chassis is a typical nonlinear system, more and more researches are focused on the nonlinear characteristics of vehicle dynamics to achieve precise vehicle dynamic control. However, the control of nonlinear system is always a hard task to perform. In this paper, a three-degrees-of-freedom (3DOF) planar vehicle model is built firstly, in which the nonlinear terms are considered. Then, the nonlinear model is fuzzified by the T-S fuzzy methodology based on the assumption of sector-bounded nonlinearity. Furthermore, a model-based fuzzy controller of Parallel Distributed Compensation (PDC) is employed, and the controller shares the same fuzzy sets with the T-S fuzzy model. The Linear Matrix Inequality (LMI) technology is utilized to solve the feedback gains for the PDC controller to ensure its performance of the closed-loop control system. Finally, the proposed algorithm is simulated by Matlab/Simulink and CarSim.
2016-04-05
Technical Paper
2016-01-1112
Byeong wook Jeon, Sang-Hwan Kim, Donghoon Jeong, Joseph Young-il Chang
In general, driving performance development of a vehicle is focused on satisfying preference of average customers. But there is no single standardized setup which can fulfill various driving tastes of all drivers, since they are different by gender, culture, age group, and personal habits. To resolve this issue, automotive companies have introduced selectable drive mode buttons which drivers can manually select desired drive mode among Normal, Eco, and Sport. These manually selected multi-mode systems provides variety of choices than single-mode system, but it still is a transitory solution which induces inconvenience of requiring drivers' effort to select and frequently change preferred drive mode in volatile driving situations. Also, it is a questionable supposition that categorizing complex needs of drivers into 3 modes is sufficient.
2016-04-05
Technical Paper
2016-01-1004
Somendra Pratap Singh, Shikhar Asthana, Shubham Singhal, Naveen Kumar
The energy crisis coupled with depleting fuel reserves and rising emission levels has encouraged research in the fields of performance and emission enhancement technologies and engineering designs. The present paper aims primarily to offset the problem of high emissions and low efficiency in low cost CI engines used as temporary power solutions on a large scale. The investigation relates to the low cost optimization of an intake runner having the ability to vary the swirl ratio within the runner. The test runs conducted for the intake revealed an increase in efficiency at the cost of increased NOx and CO2 (for some configurations) and at the same time, the UHC and CO emissions were considerably decreased. However, in a relative analysis, no configuration was able to simultaneously reduce all emission parameters and thus, there exists a necessity to find an optimized configuration as a negotiation between the improved and deteriorated parameters.
2016-04-05
Technical Paper
2016-01-0606
Chaitanya Wadkar, Bassem H. Ramadan
A numerical and experimental study of the use of air motion control, piston bowl shape, and injector configuration on combustion and emissions in diesel engines has been conducted. The objective of this study is to investigate the use of flow control within the piston bowl during compression to enhance fuel air mixing to achieve a uniform air-fuel mixture to reduce soot and NO emissions. In addition to flow control different piston bowl geometries and injector spray angles have been considered and simulated using three-dimensional computational fluid dynamics and experiments. The results include cylinder pressure and emissions measurements and contour plots of fuel mass fraction, soot, and NO. The results show that soot and NO emissions can be reduced by proper flow control and piston bowl design.
2016-04-05
Technical Paper
2016-01-0761
Mohammad Izadi Najafabadi, Nico Dam, Bart Somers, Bengt Johansson
Partially Premixed Combustion (PPC) is a promising combustion concept for future IC engines. However, controllability of PPC is still a challenge and needs more investigation. The scope of the present study is to investigate the ignition sensitivity of PPC to injection timing at different injection pressures. To better understand this, shadowgraphy method is used to visualize fuel injection and evaporation at different Start of Injections (SOI). Injection penetration and spray targeting are derived from shadowgraphy movies. As well as this, OH* Chemiluminescence is used to comprehensively study the stratification level of combustion which is helpful for interpretation of ignition sensitivity behaviors. Mathematical analysis of Chemiluminescence images is performed to extract the level of stratification from different combustion strategies. Shadowgraphy results confirm that SOI strongly affects the injection penetration and evaporation of fuel.
2016-04-05
Technical Paper
2016-01-0546
Henry McCabe, William F. Northrop, James Van de Ven
The impact of compression ratio on engine indicated efficiency is well known. A plethora of mechanical concepts have been proposed for altering engine compression ratio in real time. Some of these, like free-piston configurations or complex slider-crank mechanisms, have the added ability to alter piston trajectory along with compression ratio. This secondary modality raises the question: Is there a more optimal piston position versus crank-angle profile for spark-ignition (SI) engines than the near-sinusoidal motion produced by a traditional four-bar crank-slider mechanism? Very little published literature directly addresses this question. Our previous work examined the potential of a Stephenson-III six-bar linkage to enable variable piston trajectory. This work presents the results of a quasi-dimensional SI engine model using piston trajectory as an input.
2016-04-05
Technical Paper
2016-01-1309
Yingping Lv, Yongchang Du, Yujian Wang
In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. The methods are based on a new closed-loop coupling disc break model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived. Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode. Substructure modal parameters sensitivity analysis calculates the sensitivity of each component’s modal frequencies and shape coefficients to the real part of eigenvalues. Finally, the presented analysis methods are applied to analysis a high frequency squeal problem of a squealing disc brake.
2016-04-05
Technical Paper
2016-01-1059
Huyao Wu, Fei Huo
In this paper, as the common principle of some engineering applications, a compound pendulum consists of two bodies and relevant force elements, of springs and dampers is considered, whose governing equations are created as Newton’s Second Law, which is the ordinary differential equations (ODES) with the periodic time-variant coefficients and non-autonomous system. Further combine the engineering cases based on the G. Floquet Theory, the numeric analysis whose different types of solutions are examined, the stability problem for the time variant ODES on the zero-solutions is discussed. Relevant stability diagram and various responses are provided for different kinds of excitations, kinetic and dynamic parameters. Finally discuss the application of principles and phenomenon in automotive field.
2016-04-05
Technical Paper
2016-01-1449
Taylor Johnson, Rong Chen, Rini Sherony, Hampton C. Gabler
Road departure crashes are one of the most dangerous crash modes in the United States. When the vehicle drifts out of lane and departs the roadway, it has a higher potential of impacting less compliant objects, such as trees, poles, as well as oncoming vehicles. In the U.S., road departure crashes account for 10% of all crashes, but is responsible for over 30% of all vehicle occupant fatalities. Lane departure warning (LDW) systems can detect an impending road departure and deliver an alert to allow the driver to steer back to the lane. LDW has great potential to reduce the number of road departure crashes, but the effectiveness is highly dependent upon driver acceptance. However, if the driver perceives there is little danger after receiving an alert, the driver may become annoyed and deactivate the system. Most current LDW systems rely heavily upon distance to lane boundary (DTLB) in the decision to deliver an alert.
2016-04-05
Technical Paper
2016-01-1457
John M. Scanlon, Kerry Page, Rini Sherony, Hampton C. Gabler
Intersection Advanced Driver Assist Systems (I-ADAS) are emerging, vehicle-based active safety systems that aim to help drivers safely navigate intersections. These systems can detect a potential intersection-related crash and provide either a warning to the driver or activate automatic braking/steering. This paper presents a strategy for reconstructing the pre-crash trajectories of vehicles in real-world cross traffic crashes which might be mitigated using I-ADAS. The crashes were then simulated as if either vehicle was equipped with a side or forward facing radar system. This study is based on evidence collected from 48 crashes (96 vehicles) within the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) years 2004 to 2014. Pre-crash kinematics were generated using vehicle positions indicated by the investigator-generated scene diagram and pre-crash event data recorder (EDR) records. Two main research questions were posed in this study.
2016-04-05
Technical Paper
2016-01-0454
Hongyu Zheng, Shenao Ma
As a new braking system, EHB can significantly improve the braking performance and vehicle handling and stability. A number of factors impacts the EHB system characteristics, wheel cylinder pressure are regulated by in-solenoid and out-solenoid valve, the dynamic response of the control strategy will impact the accuracy of wheel cylinder pressure greatly. In this paper the structure of high-speed on-off valve and the valve core principle are discussed, the paper also analysis the response of the valve core under different modulation frequency and duty cycle and the change of wheel cylinder pressure. Setting a proper modulation frequency to make sure that electromagnetic valve can be worked in a greater linear range.
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
Technical Paper
2016-01-0146
Yonghwan Jeong, Seonwook Kim, Kyongsu Yi, Sangyong Lee, ByeongRim Jo
This paper represents the parking lot occupancy detection algorithm and the parking control algorithm for autonomous valet parking system. With the assumption that the global parking map exists, the occupancy of the parking space is measured using a two-dimensional Light Detection and Ranging (LIDAR) sensor mounted at each side of front bumper. The Euclidean minimum spanning tree (EMST) method is used to cluster the point information from LIDAR. The global parking map includes all parking lots and access road. The proposed parking control algorithm consists of a desired path generation, a path tracking controller, and a parking process controller. At first, route points of the desired path are determined under the consideration of the minimum turning radius and minimum safety margin with near parking spaces. The desired path is generated by connecting straight lines and arcs between pre-determined route points.
2016-04-05
Technical Paper
2016-01-1266
Shinichi Urabe, Kazutaka Kimura, Yuki Kudo, Akinori Sato
Green energy technologies attract people’s interests these years due to decrease the effect of global warming, which might be caused by CO2 and other emission gases. Solar energy can be one of solutions for global warming. Several countries have introduced photovoltaic energy system as their electric power sources yet, furthermore some factories and individual homes also has established photovoltaic energy system on their roof. The tendencies like the above seem to become more popular in the future. A car that is driven by electric power from photovoltaic energy system can help decreasing the amount of CO2 gas exhausted from cars. However, conventional cars are not easy to be equipped with solar modules like vehicles for solar car racing, because the area where the system can be set on is very small to keep cabin space, and car’s body-line is usually round slightly.
2016-04-05
Technical Paper
2016-01-0469
Hyunkoo Kang, Wooyong Jung, Choon Lee
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
Journal Article
2016-01-1278
Shubhangi S. Nigade
This paper presents a new effective approach involve an application of Taguchi method and grey relational analysis used to determine the optimum factor and the level of experimental results. To obtain optimum multiple performance characteristics of diesel engine run with madhuca indica biodiesel, diesel and its blend. The approach combines the orthogonal array design of experiments with grey relational analysis. Grey relational theory is adopted to determine the best input parameters that give lower emission and higher performance of engine. Six design parameters namely; compression ratio, injection pressure, injection nozzle geometry, additive and fuel fraction were selected, and five levels for each factor. To reduce an experimental effort the experiments have been performed by employing Taguchi's L16 orthogonal array for various engine performance and emission related responses. Injection nozzle geometry and compression was found to most influencing factors.
2016-04-05
Technical Paper
2016-01-1592
Yuji Kobayashi, Itsuhei Kohri, Akira Kasai, Takayoshi Nasu, Daichi Katoh, Yoshimitsu Hashizume
In the previous report, the unsteady wake of the Ahmed model has been investigated experimentally using hot-wire and PIV measurement. Furthermore, the hypothesis how the drag crisis is occurred was presented in a paper titled “Experimental Analysis on the Transitional Mechanism of the Wake Structure of the Ahmed Body”. However, since the experimental analysis had the limited data, the spatial unsteady wake behavior, interaction between such the trailing vortex and transverse vortices (up/down-wash) and flow mechanism near the body has not been discussed sufficiently. Then, the unsteady wake has been analyzed computationally using PowerFLOW5.1B to understand the issues mentioned above and then the hypothesis was tested. The slant angle employed 27.5°which was identical angle with experiment and was high drag condition indicated experimentally. Preliminary to analysis the flow phenomena, following components were confirmed.
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
Journal Article
2016-01-0468
Jiageng Ruan, Paul Walker, Nong Zhang, Guangzhong Xu
Regenerative braking has been widely accepted as a feasible option to extend the mileage of electric vehicles (EVs) by recapturing the vehicle’s kinetic energy instead of dissipating it as heat during braking. The regenerative brake force provided by a generator is applied on the wheels in an entirely different manner compared to the traditional hydraulic-friction brake system. Drag torque and efficiency loss may be generated by transmitting the braking force from motor, axles, differential and, specifically in this paper, a two-speed dual clutch transmission (DCT) to wheels. Additionally, motors in most battery EVs (BEVs) and hybrid electric vehicle (HEVs) are only connected to front or rear axle. Consequently, conventional hydraulic brake system is still necessary, but dynamic and supplement to motor brake, to meet particular brake requirement and keep vehicle stable and steerable during braking.
2016-04-05
Journal Article
2016-01-0477
Pu Gao, Yongchang Du, Yujian Wang, Yingping Lv
The dynamic properties of disc rotor play important role in the NVH performance of a disc brake system. Disc rotor in general is a centro-symmetric structure. It has many repeated-root modes within the interested frequency range and they may have significant influence on squeal occurrence. A pair of repeated-root modes is in nature one vibration mode. However, in current complex eigenvalue analysis model and relevant analysis methods, repeated-root modes are processed separately. This may lead to contradictory result. This paper presents methods to deal with repeated-root modes in substructure modal composition (SMC) analysis to avoid the contradiction. Through curve-fitting technique the modal shape coefficients of repeated-root modes are expressed in an identical formula. This formula is used in SMC analysis to obtain an integrated SMC value to represent the total influence of two repeated-root modes.
2016-04-05
Journal Article
2016-01-1318
Syed F. Haider, Zissimos Mourelatos
Finite element analysis is a standard tool for deterministic or probabilistic design optimization of dynamic systems. Such an optimization requires repeated eigenvalue analyses which can be very expensive. Several reanalysis techniques have been proposed to reduce the computational cost including Parametric Reduced Order Modeling (PROM), Combined Approximations (CA), and the Modified Combined Approximations (MCA) method. However, the cost of reanalysis can be still large for models with a large number of degrees of freedom and a large number of design variables. Reanalysis methods use a basis composed of eigenvectors from both the baseline and the modified designs which are in general linearly dependent. To eliminate the linear dependency and improve accuracy, Gram Schmidt orthonormalization is employed which is costly itself. In this paper, we propose a method to reduce the orthonormalization cost and improve the efficiency of the PROM reanalysis method.
2016-02-05
Magazine
Off-highway hybrids: Opportunities and challenges With oil prices declining and emissions regulations in North America 'stabilized,' is there a place for hybrid powertrains in this new world of cheap oil? Looking for a better image Display advances are helping to reduce operator fatigue. Charging up electrified powertrains Control technologies race forward while batteries improve and adopt standard sizes. Measuring and accounting for suspension TARDEC teamed with SEA Ltd. to develop a system to measure the suspension parameters, center of gravity, and moments of inertia of wheeled vehicles in the never ending quest to model and predict vehicle dynamic behavior. Looking at mobility in 2050 Cuneyt L. Oge begins his term as 2016 SAE International President with a vision about the future of auto- and aero-mobility.
2016-02-01
Technical Paper
2016-28-0171
Kaushal Kumar Darpkar, Anand Bidre
Abstract Primary function of a drive half shaft is to transfer torque from transaxle to the wheels in East West configuration powertrain vehicles. Conventional practice is to consider either 1st gear max torque or the Wheel slip torque, whichever being the maximum as design torque. However vehicle dynamics and Powertrain characteristics have a major influence on the Driveshaft torque and the torques experienced can thus go beyond the design torque. This questions the design endurance limit for the driveshaft based on conventional design. One such situation is the torque experienced by the driveshaft during vehicle coasting condition with gear downshift. The torque experienced in such a scenario can go beyond the maximum design torque leading to failure as was observed in Vehicle level validation test.
2016-02-01
Technical Paper
2016-28-0172
Praharsh Srivastava, Kamal Sharma, Raushan Jha
Abstract Rapid advent of mobile air conditioning industry has witnessed a wide use of fixed displacement swash plate compressor due to its small size, compact structure and light weight. An accurate prediction of volumetric efficiency and power of compressor at early stages of design serves as a very useful information for designer. No work regarding the power and volumetric efficiency prediction for double headed fixed displacement swash plate compressor is reported in the existing literature. This paper presents a mathematical model for a double acting fixed displacement swash plate compressor with the objective of evaluating the shaft torque and volumetric efficiency of compressor. Shaft torque, in turn is a measure of compressor power. The geometrical description of swash plate yields a kinematic model to obtain the piston displacement as an explicit function of angle of rotation of shaft.
2016-02-01
Technical Paper
2016-28-0184
Aditya Anant Patil
Abstract Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input.
Viewing 1 to 30 of 2648

Filter

  • Range:
    to:
  • Year: