共查询到20条相似文献,搜索用时 31 毫秒
1.
H. J. Kim B. Han W. S. Hong W. H. Shin G. B. Cho Y. K. Lee Y. J. Kim 《International Journal of Automotive Technology》2010,11(4):447-453
A 3000 cc diesel engine attached to an engine dynamo was used to test three newly developed electrostatic Diesel Particulate
matter filtration Systems (DPS 1, 2, and 3) under four steady-state engine operating conditions: idle, 2000 rpm with no load,
and 2000 rpm under 25% and 50% loads. Of the two developed alternatives, DPS 1 and DPS 2, DPS 2 comprises an ionization section,
electrostatic field additional section and Flow-Through Filter (FTF), which achieved almost 90% removal of particulate matter
(PM) under the engine’s operating conditions, and the efficiency of the FTF was maintained between 20% and 50%. Comparing
the long-term performance of DPS 2 and DPS 3 (effectively a serial combination of two DPS 2s) with a commercially-available
Diesel Particulate Filter (DPF), the DPS 2 and DPS 3 achieved almost the same efficiency for removing PM as the DPF but had
significantly improved (75%∼90% lower) differential pressure drops. 相似文献
2.
Bogdan Tolea Alexandru Ionut Radu Horia Beles Csaba Antonya 《International Journal of Automotive Technology》2018,19(1):85-98
The goal of this paper is to determine how the geometry of the vehicle’s frontal profile is influencing the pedestrian’s head accelerations (linear and angular) in car-to-pedestrian accidents. In order to achieve this goal, a virtual multibody dummy of the pedestrian was developed and multiple simulations of accidents were performed using vehicles with different frontal profile geometry, from different classes. The type of accidents considered is characteristic for urban areas and occur at relatively low speed (around 30 km/h) when an adult pedestrian is struck from the rear and the head acceleration variation are the measurement of the accident severity. In the accident simulation 3D meshes were applied on the geometry of the vehicles, in order to define the contact surface with the virtual dummy, similar with real vehicles. The validation of the virtual pedestrian dummy was made by performing two crash-tests with a real dummy, using the same conditions as in the simulations. The measured accelerations in the tests were the linear and angular accelerations of the head during the impact, and these were compared with the ones from the simulations. After validating the virtual model of the car-to-pedestrian accident, we were able to perform multiple simulations with different vehicle shapes. These simulations are revealing how the geometric parameters of the vehicle’s frontal profile are influencing the head acceleration. This paper highlights the main geometric parameters of the frontal profile design that influence the head injury severity and the way that the vehicles can be improved by modifying these parameters. The paper presents an approach to determine the “friendliness” of the vehicle’s frontal profile in the car-to-pedestrian collision. 相似文献
3.
S. -J. Kim W. -J. Jeon J. -J. Park B. -S. Moon Y. -J. Cho Y. -I. Seo N. -K. Park K. Son 《International Journal of Automotive Technology》2011,12(6):951-958
A perturbation mark is occasionally produced on the velocity indicator of the cluster panel of a vehicle during a vehicle
collision. This mark can be used to estimate the velocity of the vehicle at the moment of the vehicle’s impact. In this study,
the effect of the impact velocity and the deceleration of the vehicle on the perturbation mark were investigated, and an analysis
of the driver’s injury was also conducted through a numerical pulse representation and computer simulations. Sled and pendulum
tests were used to replicate the conditions that produce a perturbation mark on the velocity indicator of a cluster panel.
It was verified that a higher peak acceleration is more likely than the impact velocity to cause a perturbation mark. According
to the computer simulation results, a driver’s injury could be more severe at higher peak accelerations with a constant impact
velocity. If a perturbation mark, which can be used to estimate the impact velocity, is found while investigating a vehicle
accident, this mark reveals that the acceleration was higher than that listed in the related crash report. Therefore, the
injuries of the occupants could be more serious than those expected at the reported impact velocity. 相似文献
4.
Head injuries are a major cause of fatalities in pedestrian-car accidents. The HIC (Head Injury Criterion) value, a measure of the fatality risk of a head injury, is calculated from the acceleration of the head’s center of gravity
(henceforth, head center) resulting from a head impact. The pedestrian’s head does not impact the hood at a direction normal
to the hood’s surface. The direction of motion of the head center may change extremely rapidly upon impact, and normal acceleration
may also significantly contribute to the resultant acceleration of the head center. Therefore, pedestrian head protection
studies should consider how normal acceleration contributes to the resultant acceleration of the head center. It is necessary
to control the resultant acceleration of the head center to produce an optimal characteristic pulse. This study analyzes the
composition and variations of the head’s acceleration in head-to-hood impacts, focusing on exactly how the normal and tangential
components of the acceleration contribute to the resultant acceleration of the head center. This study also considers how
structural design parameters affect each component of the resultant acceleration. Methods to control the resultant acceleration
of the head center to produce an optimal characteristic pulse can be proposed based on the results of this study. The analytical
models and the results of this study contribute to efforts to design vehicle hoods and pave the way for developing pedestrian
protection technologies. 相似文献
5.
This study proposes a design for an idle speed controller to compensate for varying engine load and friction torque in passenger car diesel engines. An active disturbance rejection control (ADRC) framework, comprised of a disturbance compensator and a feedback controller, is applied to an idle speed controller to compensate for disturbances such as engine load and friction torque. In addition, a feedforward compensator is designed into the ADRC framework to improve disturbance rejection performance. The proposed controller is validated by engine and vehicle experiments and the experiment results are compared with a commercial controller. 相似文献
6.
J. Galindo H. Climent C. Guardiola J. Doménech 《International Journal of Automotive Technology》2009,10(2):141-149
Parallel sequential turbocharging systems are able to operate in different modes, which are defined according to the turbochargers
that simultaneously boost the engine, and are controlled by means of specific valves. In order to cover the full engine operating
range, a smooth transition between turbocharging operating modes must be ensured. However, important disturbances affect both
boost and exhaust pressure when shifting the operation mode, thus causing non-negligible torque oscillations. This paper presents
different methods for smoothing such undesirable effects during mode transition. Strategies covering optimal synchronization
of the control valves, control of the valves’ position, and correction of the injected fuel during the transition are analysed.
A fully instrumented passenger car engine is used for illustrating the different torque smoothing methods, and experimental
results for transitions during both steady operation and engine accelerations are shown. 相似文献
7.
汽油机采用VVA可改善怠速稳定性,提高中低速外特性扭矩,往往也有一定的节油效果。但VVA机构研制难度很大,目前只有个别机构实用。作者研制了一个采用双级谐波传动的调相机构。试验表明,该机构能圆满实现调相功能,其长期工作的可靠性也经受了一定考验,考察了调相对发动机充量系数的影响,计算和实测结果基本一致,在全部转速范围内,充量系数都有提高。 相似文献
8.
Low viscosity engine oil can improve a vehicle’s fuel economy by decreasing the friction between the engine components. Frictional
torque varies with the velocity change due to different viscosity characteristics of SAE grade 5W-20, 5W-30 and 5W-40 engine
oils. The viscosity for each of these grades was measured to outline the effect low viscosity engine oils have on engine friction,
which may lead to improved fuel economy. Engine oil seal frictional torque increases with the shaft rotational speed for all
three engine oil grades. A decrease in engine oil seal frictional torque was confirmed when low viscosity engine oil was used.
Also, the leak-free performance of the engine oil with the seal satisfied the life limit durability test criteria. Thus, low
viscosity engine oil may be used to improve fuel economy by decreasing the frictional loss of the engine oil seal while having
no negative impact on performance due to leak-free functioning. 相似文献
9.
10.
Torque is one of the most important control factors for a vehicle’s motion. Compared with internal combustion engines, electric motors can have a more accurate torque feedback which brings a lot of advantages to vehicle dynamics and stability control. However, motors used in electric vehicles are facing more difficult conditions than those in conventional applications, such as extreme high/low temperature changing, vibration, aging, etc. The variation of motor parameters due to harsh working conditions can lead to serious problems for motor torque estimation and thus dynamic control of electric vehicles. In this paper, a new method using kriging to estimate the back EMF and thus accurately calculate motor torque in an on-line fashion is presented. With motor speed and rotor position as inputs, kriging predicts back EMF as the output that is used to calculate the motor torque with three phase currents. Using this novel method, motor torque can be accurately calculated even facing high/low temperatures or aging conditions. Experimental tests under the high temperature have been conducted to verify the applicability of the proposed method. 相似文献
11.
12.
Minimizing the engine-induced harshness based on the DOE method and sensitivity analysis of the full vehicle NVH model 总被引:1,自引:0,他引:1
An efficient procedure for minimizing the engine-induced harshness based on NVH analysis results of a full vehicle model was
developed in this study, taking stiffness and strength constraints into account. Although extensive research may be found
in the literature in the field of engine support system optimization, no other studies have considered the compliances and
resonances of the structure of the vehicle. In the present paper, NVH analysis results of the whole vehicle were used in an
optimization procedure to suppress the transmitted vibration. A procedure was developed to minimize the transmitted accelerations
to the mid-point of the driver’s seat rail. A DOE-based response surface methodology (RSM) was adopted to determine the optimal
solution. Natural frequencies of the body, suspension, and other subsystems were taken into consideration in determining the
optimal solution. NVH analysis was performed for two types of inputs: (a) vertical vibration due to vertical unbalanced forces
and (b) torsional vibration due to oscillations in the output torque of the engine. 相似文献
13.
14.
大客车大部分采用后置发动机,驾驶区保温性能比较差。高寒地区大客车驾驶区采暖性能的好坏直接影响到驾驶员的舒适性和行车的安全性。本文根据市场上大客车驾驶区采暖存在的问题,进行简要分析并提出解决措施。 相似文献
15.
Independent control of all-wheel-drive torque distribution 总被引:1,自引:0,他引:1
Russell P. Osborn Taehyun Shim 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(7):529-546
The sophistication of all-wheel-drive (AWD) technology is approaching the point where the drive torque to each wheel can be independently controlled. This potentially offers vehicle handling enhancements similar to those provided by dynamic stability control, but without the inevitable reduction in vehicle acceleration. Independent control of AWD torque distribution would therefore be especially beneficial under acceleration close to the limit of stability. A vehicle model of a typical sports sedan was developed in Simulink, with fully independent control of torque distribution. Box-Behnken experimental design was employed to determine which torque distribution parameters have the greatest impact on the vehicle course and acceleration. A proportional-integral control strategy was implemented, applying yaw rate feedback to vary the front-rear torque distribution and lateral acceleration feedback to adjust the left-right distribution. The resulting system shows a significant improvement over conventional driveline configurations under aggressive cornering acceleration on a high-μ surface. The performance approaches the theoretical limit for these conditions. In the medium term, such a system is only likely to be economically viable for premium vehicles. However, a future revolution of powertrain technology towards, for example, wheel-mounted motors, could realize these handling benefits far more widely. 相似文献
16.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3):343-362
A new device for an objective evaluation of ground vehicle ride comfort is presented. In this study, the ride comfort (frequency range 0–30 Hz) has been referred to the acceleration acting along the vertical axis (subject spine) and to the longitudinal acceleration (acting at the subject shoulders). Based on the experimental measurements of such accelerations on different human subjects seated on a car seat, a proper mechanical/mathematical model of the seat+subject has been derived. The derivation of the model has been performed by minimising the error between the measured and the computed accelerations. A prototype of the derived mechanical model has been actually built. Particular attention has been devoted to the construction of the springs, of the moving members and of the magnetic damper. All of the device parameters (mass, stiffness, damping) can be easily tuned. Finally, an experimental validation of the device has been performed. The device, while seated with the same posture of the corresponding human subject is able to reproduce (with reasonable accuracy) both the acceleration along the subject spine and the acceleration at the subject shoulders. 相似文献
17.
18.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(7):529-546
The sophistication of all-wheel-drive (AWD) technology is approaching the point where the drive torque to each wheel can be independently controlled. This potentially offers vehicle handling enhancements similar to those provided by dynamic stability control, but without the inevitable reduction in vehicle acceleration. Independent control of AWD torque distribution would therefore be especially beneficial under acceleration close to the limit of stability. A vehicle model of a typical sports sedan was developed in Simulink, with fully independent control of torque distribution. Box–Behnken experimental design was employed to determine which torque distribution parameters have the greatest impact on the vehicle course and acceleration. A proportional-integral control strategy was implemented, applying yaw rate feedback to vary the front–rear torque distribution and lateral acceleration feedback to adjust the left–right distribution. The resulting system shows a significant improvement over conventional driveline configurations under aggressive cornering acceleration on a high-μ surface. The performance approaches the theoretical limit for these conditions. In the medium term, such a system is only likely to be economically viable for premium vehicles. However, a future revolution of powertrain technology towards, for example, wheel-mounted motors, could realize these handling benefits far more widely. 相似文献
19.
M. S. Wang N. T. Jeong K. S. Kim S. B. Choi S. M. Yang S. H. You J. H. Lee M. W. Suh 《International Journal of Automotive Technology》2016,17(1):165-173
Drowsy behavior is more likely to occur in sleep-deprived drivers. Individuals’ drowsy behavior detection technology should be developed to prevent drowsiness related crashes. Driving information such as acceleration, steering angle and velocity, and physiological signals of drivers such as electroencephalogram (EEG), and eye tracking are adopted in present drowsy behavior detection technologies. However, it is difficult to measure physiological signal, and eye tracking requires complex experiment equipment. As a result, driving information is adopted for drowsy driving detection. In order to achieve this purpose, driving experiment is performed for obtaining driving information through driving simulator. Moreover, this paper investigates effects of using different input parameter combinations, which is consisted of lateral acceleration, longitudinal acceleration, and steering angles with different time window sizes (i.e. 4 s, 10 s, 20 s, 30 s, 60 s), on drowsy driving detection using random forest algorithm. 20 s-size datasets using parameter combination of accelerations in lateral and longitudinal directions, compared to the other combination cases of driving information such as steering angles combined with lateral and longitudinal acceleration, steering angles only, longitudinal acceleration only, and lateral acceleration only, is considered the most effective information for drivers’ drowsy behavior detection. Moreover, comparing to ANN algorithm, RF algorithm performs better on processing complex input data for drowsy behavior detection. The results, which reveal high accuracy 84.8 % on drowsy driving behavior detection, can be applied on condition of operating real vehicles. 相似文献
20.
转向力是汽车操纵稳定性中一项重要的评价指标,其力矩波动直接影响驾驶感觉。文章对汽车转向轴的布置与力矩波动的关系进行了分析,并针对某车型转向系统的十字轴万向节结构进行优化设计。优化结果在matlab软件里仿真,得到较好的结果,波动力矩在允许的范围内。并得出最佳的中间轴相位角及轴系布置方案,对转向系统的优化设计有一定的参考价值,可作为实际车型开发中传动优化设计的技术依据。 相似文献