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Technical Paper

Finite Element Analysis of Light Vehicle Cab's Hydraulic Mount Based on Fluid-Structure Interaction Method

2011-05-17
2011-01-1604
Hyperelastic model constants of rubber material are predicted based on test date. The fluid-structure interaction model of light vehicle cab's hydraulic mount is established. Static characteristics of the hydraulic mount are analyzed by quasi-static method. In dynamic characteristics analysis, the flow model of fluid is set to turbulent K-Epsilon RNG. The dynamic stiffness and loss angle of the hydraulic mount are presented via the finite element model. The simulations of static and dynamic characteristics agree well with corresponding test results. The effects of main structure parameters to the dynamic characteristics of the hydraulic mount are analyzed based on the finite element model.
Technical Paper

Experimental Investigation on Particle Number and Size Distribution of a Common Rail Diesel Engine Fueling with Alternative Blended Diesel Fuels

2011-04-12
2011-01-0620
An EURO 3 certified common rail diesel engine was fueled with pure petroleum diesel (EURO 4 standard) and three different alternative blended diesel fuels, 10% biodiesel blended diesel (B10), 10% gas to liquid blended diesel (G10) and 10% water emulsified diesel (E10). Tests were performed at different engine speeds and load states. Particle number concentration and size distribution data were obtained from an engine exhaust particle sizer (EEPS). Over all the working conditions, total particle and nucleation mode particle number concentration among these fuels from high to low were in this order: B10, E10, pure diesel and G10. Proportions for nucleation mode particle over all the operating states in that order were 89%, 82%, 59% and 66%. Particle size distributions of B10 and E10 presented bimodal logarithmic distributions with outstanding nucleation mode peaks at all working conditions.
Technical Paper

Automobile Interior Noise Prediction Based on Energy Finite Element Method

2011-04-12
2011-01-0507
For the purpose of predicting the interior noise of a passenger automobile at middle and high frequency, an energy finite element analysis (EFEA) model of the automobile was created using EFEA method. The excitations including engine mount excitation and road excitation were measured by road experiment at a speed of 120 km/h. The sound excitation was measured in a semi-anechoic chamber. And the wind excitation was calculated utilizing numeric computation method of computational fluid dynamics (CFD). The sound pressure level (SPL) and energy density contours of the interior acoustic cavity of the automobile were presented at 2000 Hz. Meanwhile, the flexural energy density and flexural velocity of body plates were calculated. The SPL of interior noise was predicted and compared with the corresponding value of experiment.
Journal Article

Investigation on Dynamic Recovery Behavior of Boron Steel 22MnB5 under Austenite State at Elevated Temperatures

2011-04-12
2011-01-1057
Hot forming process of ultrahigh strength boron steel 22MnB5 is widely applied in vehicle industry. It is one of the most effective approaches for vehicle light weighting. Dynamic recovery is the major softening mechanism of the boron steel under austenite state at elevated temperatures. Deformation mechanism of the boron steel can be revealed by investigation on the behavior of dynamic recovery, which could also improve the accuracy of forming simulations for hot stamping. Uniaxial tensile experiments of the boron steel are carried out on the thermo-mechanical simulator Gleeble3800 at elevated temperatures. The true stress-strain curves and the relations between the work hardening rate and flow stress are obtained in different deformation conditions. The work hardening rate decreases linearly with increasing the flow stress.
Technical Paper

Vibration Characteristic Analysis and Optimization of the Rear Suspension of Eccentrical Motor Driven Electric Vehicle

2013-03-25
2013-01-0088
To wheel driven electric vehicle, besides road unevenness excitation, the electric motor torque fluctuation has great effects on the whole body vibration (WBV) according to prior research.[1],[2] To evaluate and further reduce the influence of torque fluctuation on the whole body vibration (WBV), vibration characteristic of rear suspension is analyzed thoroughly and finally optimized in this paper. Firstly, based on an existing eccentrical motor driven electric vehicle, a rear twist beam suspension suitable for high frequency analysis is modeled in Adams/View. Secondly, the vibration characteristic is simulated using Adams/Vibration module and verified with natural modal parameters of system. Finally, the vibration characteristic is optimized by adjusting the parameters of bushings using DOE method and proven to be effective to reduce WBV caused by torque fluctuation.
Technical Paper

The Bus Monitoring and Fault Diagnosis System Design of Hybrid Vehicle Based on Embedded System

2010-10-05
2010-01-1992
Embedded bus monitoring and fault diagnosis system, which was used on the hybrid vehicle was designed in this paper. And this system took the 32-bit embedded one as a hardware platform, customized a WinCE6.0 operation system and used EVC as the tool to design the embedded application. The functions of CAN communication, protocol defamations etc were realized. Good human-computer interaction is developed and the system has already been applied on the bus.
Technical Paper

Reducing Part Load Pumping Loss and Improving Thermal Efficiency through High Compression Ratio Over-Expanded Cycle

2013-04-08
2013-01-1744
In vehicle application, most of time gasoline engines are part load operated, especially in city traffic, part load operation covers most common operation situations, however part load performances deteriorate due to pumping losses and low thermal efficiency. Many different technologies have been applied to improve part load performances. One of them is to adopt over-expanded (Atkinson/Miller) cycle, which uses late/early intake valve closing (LIVC/EIVC) to reduce pumping losses in part load operation. But over-expanded cycle has an intrinsic drawback in that combustion performance deteriorates due to the decline in the effective compression ratio (CR). Combining with high geometry CR may be an ideal solution, however there is a trade-off between maintaining a high CR for good part load fuel consumption and maintaining optimal combustion phasing at higher load.
Technical Paper

Development and Evaluation of the Performance Characteristics of a Poly-Disperse Droplet Stream Generator

2013-04-08
2013-01-1617
A specially designed generator has been developed to produce poly-disperse droplet streams: A liquid fuel (n-heptane) is metered to an ultrasonic atomizer to produce droplets, which are then carried and accelerated vertically upwards through a nozzle tube by carrier-air flow. Conditions of the streams at the nozzle exit are modulated by varying the length of nozzle tubes, the fuel and carrier-air flow rate. Optical measurement techniques such as direct photography method, schlieren photography and particle image velocimetry (PIV) are employed to characterize its performance characteristics. Effects of the nozzle tube length, the carrier-air and fuel flow rate are investigated to evaluate the performance of the generator. Longer nozzle tubes provide a better flow guidance for the carrier-air, and tend to generate streams with less and smaller droplets due to the transporting losses.
Technical Paper

Fault Tolerant Control Against Actuator Failures of 4WID/4WIS Electric Vehicles

2013-04-08
2013-01-0405
A fault tolerant control (FTC) approach based on reconfigurable control allocation for four-wheel independently driven and steered (4WID/4WIS) electric vehicles against driving motor failures is proposed in order to improve vehicle safety, performance and maneuverability after the driving motor failures. The proposed fault tolerant control method consists of the following three parts: 1) a fault detection and diagnosis (FDD) module that monitors vehicle driving condition, detects and diagnoses actuator failures; 2) a motion controller that computes the generalized forces/moments to track the desired vehicle motion using model predictive control method; 3) a reconfigurable control allocator that optimally distributes the generalized forces/moments to four wheels aiming at minimizing the total tire usage. The FTC approach is based on the reconfigurable control allocation which reallocates the generalized forces/moments among healthy actuators once the actuator failures is detected.
Technical Paper

A Model-Based Mass Estimation and Optimal Braking Force Distribution Algorithm of Tractor and Semi-Trailer Combination

2013-04-08
2013-01-0418
Taking a good longitudinal braking performance on flat and level road of tractor and semi-trailer combination as a target, in order to achieve an ideal braking force distribution among axles, while the vehicle deceleration is just depend on the driver's intention, not affected by the variation of semi-trailer mass, the paper proposes a model based vehicle mass identification and braking force distribution strategy. The strategy identifies the driver's braking intention via braking pedal, estimates semi-trailer's mass during the building process of braking pressure in brake chamber, distributes braking force among axles by using the estimated mass. And a double closed-loop regulation of the vehicle deceleration and utilization adhesion coefficient of each axle is presented, in order to eliminate the bad effect of mass estimation error, and enhance the robustness of the whole algorithm. A simulation is conducted by utilizing MATLAB/Simulink and TruckSim.
Technical Paper

The Algorithmic Research of Multi-operating Mode Energy Management System

2013-04-08
2013-01-0988
The traditional energy management algorithm is mainly based on a single driving cycle, it is obvious that many factors might be often neglected by designer, such as different driving cycles would suit for different control strategies. But they tend to make decisions on the balance of torque distribution and battery power that based on a single driving cycle. Therefore, it is very difficult to achieve the optimal control in each case. In this paper we introduce a new design concept of Multi-operating mode energy management, a mathematical model of the energy management applied to a hybrid vehicle system is presented. Results of simulations using the model with the Multi-operating mode energy management were compared with results of simulations using a model with the single mode energy management, allowing the energy efficiency evaluation of the proposed energy management system.
Technical Paper

Fatigue Life Prediction of Rubber Bushing in Engine Cradle

2013-04-08
2013-01-1425
Fatigue defect and failure of rubber element widely used in mechanical systems could seriously affect the safety and reliability of systems in practical operation. Because rubber element is considered as hyperelastic material, traditional σ - N curve which is usually used in metal material for fatigue life analysis can not be used here. The fatigue life of rubber bushing in automobile engine cradle was analyzed by using the energy method. The Yeoh model coefficients were given by tensile test of natural rubber, and the estimating formula for fatigue life of natural rubber was obtained by finite element calculation and fatigue test. Maximum strain energy density was treated as the parameter of fatigue damage, then the rubber bushing fatigue life was calculated by the estimating formula. The results were verified by test of rubber bushing, which indicated that the model mentioned in this paper is accuracy enough.
Journal Article

Analysis of Performance Parameters of Torsional Vibration Damper Under Various Operating Conditions

2013-04-08
2013-01-1488
The performance parameters of torsional vibration damper, including stiffness and damping, have great influence on the torsional vibration of automobile driveline. At present, the research on torsional vibration damper mainly concentrates on the torsional stiffness, but rarely on the torsional damping characteristics. This paper systematically studied the effect of torsional stiffness and damping on torsional vibration of automobile driveline under uniform speed conditions, accelerated and decelerated conditions, idling conditions and resonance conditions. The requirements on stiffness and damping of various operating conditions were summarized. The effect and requirements researched were useful to performance match design of torsional vibration damper.
Technical Paper

The Effect of Multi-Universal Coupling Phase on Torsional Vibration of Drive Shaft and Vibration of Vehicle

2013-04-08
2013-01-1490
Torsional vibration of drive shaft has great influence on the vibration of vehicle. Reasonable phase arrangement of multi-universal coupling can attenuate vibration. In this paper, theoretical model of drive shaft with planar multi-cross universal coupling was established; the optimization scheme of the phase arrangement of multi-cross universal coupling was presented. The results of test validation and simulation show that the optimization scheme is effective and reasonable. The results of test validation and simulation show that the optimization scheme was effective and reasonable and the optimized scheme could solve the abnormal vibration on floor. Arranging phases of universal joints reasonably is very significative for attenuate the torsional vibration of drive shaft and the floor vibration.
Technical Paper

Study of Stability Control for Electric Vehicles with Active Control Differential

2013-04-08
2013-01-0715
This article conducts a research on the active control differential (ACD) yaw moment stability control for central motor driven automobiles. By calculation, the active control differential yaw moment generation ability which is limited by the maximum differential twist ratio and the motor output torque is not enough compared with traditional Electronic Stability Program (ESP). A Matlab and CarSim joint simulation is applied on double lane change and sine wave steering input condition, through which the active control differential effect is analyzed. It is concluded that yaw moment control using active control differential has improved the steering sensitivity and yaw rate tracking effect to some extent in double lane change test and it also has been verified that it works effectively to keep the stability of the vehicle in sine wave test.
Technical Paper

Study on Objective Evaluation Index System of On-Center Handling for Passenger Car

2013-04-08
2013-01-0714
On-center handling has drawn lots of attention from consumers and car manufactures for its extraordinarily large effect on vehicle security at high speed. So far, there are a large number of objective evaluation indices for on-center handling, but it is not clear which ones are the key points on evaluation indices. In this paper, the authors propose a simplified on-center handling objective evaluation index system. Firstly, a basic on-center handling objective evaluation index system is summarized based on the ones of ISO, GM, MIRA, TRC and Hyundai, and then dynamics analysis on each index is conducted so as to primarily eliminate the redundant indices. Secondly, the repetitive indices are cut out again by the correlation analysis among indices in objective tests for eight types of vehicles. Thirdly, the importance factor of each subjective evaluation index is gained on the basis of subjective evaluation tests for eight types of vehicles by the weighed principal component analysis.
Technical Paper

An Anti-Lock Braking Control Strategy for 4WD Electric Vehicle Based on Variable Structure Control

2013-04-08
2013-01-0717
Based on the four-wheel-drive electric vehicle (4WD EV), a variable structure control (VSC) strategy is designed in this paper for the anti-lock braking control. With nonpeak friction coefficient as target, sign judgment method of switch function in this VSC strategy is improved and a new control algorithm is proposed. The improved VSC strategy is made robust to the parameters of the algorithm and verified by the computer simulation as well as the hard-in-loop test. The results show that the slip rate can be controlled to a point in the stable area near the optimal slip ratio and the control strategy can effectively realize the anti-lock braking control.
Technical Paper

Research and Improvement of Steering Wheel's Idle Shaking

2013-04-08
2013-01-1711
Vibration tests and modal analysis method were used to recognize cause of steering wheel's idle shaking, it was found that the steering wheel's operating modal was close to engine's second order excitation frequency, which caused steering wheel's idle shaking. Five improvements were presented to relief this problem, including structural optimization, lightweight design of steering wheel, Installation of dynamic vibration absorber, matching of power train mount and reduction of engine idle speed, the effectiveness and rationality of the improvements was verified through experiments.
Journal Article

Objective Evaluation of Interior Sound Quality in Passenger Cars Using Artificial Neural Networks

2013-04-08
2013-01-1704
In this research, the interior noise of a passenger car was measured, and the sound quality metrics including sound pressure level, loudness, sharpness, and roughness were calculated. An artificial neural network was designed to successfully apply on automotive interior noise as well as numerous different fields of technology which aim to overcome difficulties of experimentations and save cost, time and workforce. Sound pressure level, loudness, sharpness, and roughness were estimated by using the artificial neural network designed by using the experiment values. The predicted values and experiment results are compared. The comparison results show that the realized artificial intelligence model is an appropriate model to estimate the sound quality of the automotive interior noise. The reliability value is calculated as 0.9995 by using statistical analysis.
Technical Paper

An Experimental Investigation of the Combustion Characteristics of Acetone-Butanol-Ethanol-Diesel Blends with Different ABE Component Ratios in a Constant Volume Chamber

2014-04-01
2014-01-1452
Acetone-Butanol-Ethanol (ABE), an intermediate product in the ABE fermentation process for producing bio-butanol, is considered a promising alternative fuel because it not only preserves the advantages of oxygenated fuel which typically emit less pollutants compared to conventional diesel, but also lowers the cost of fuel recovery for each individual component during the fermentation. With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. In this respect, it is desirable to estimate the performance of different ABE blends to determine the best blend and optimize the production process accordingly. ABE fuels with different component ratio, (A: B: E: 6:3:1; 3:6:1; 0:10:0, vol. %), were blended with diesel and tested in a constant volume chamber.
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