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排序方式: 共有882条查询结果,搜索用时 281 毫秒
271.
272.
273.
D. A. Crolla A. K. Dale 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1980,9(5):261-279
Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces
The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased
Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer 相似文献
The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased
Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer 相似文献
274.
用于补偿子弹头列车负相序电流(N.C.)的60MVA静止补偿器(STATCOM)必须成本低、体积小且效率高.为了增大容量,开发了一种IGBT串联技术.静止补偿器自2003年9月开始在中央日本铁路投入使用. 相似文献
275.
J. M. Pi Y. S. Bak Y. K. You D. H. Park H. S. Kim 《International Journal of Automotive Technology》2016,17(6):1101-1111
A route information based driving control algorithm was developed for an RE-EV which consists of two motorgenerators, MG1 and MG2. A threshold power which controls the engine on/off to charge the battery was obtained by an optimization process using route information, such as the vehicle velocity and altitude. The threshold power allows the vehicle to travel to the final destination while making the final battery SOC close to SOC low. Using the threshold power, route based control (RBC) was proposed by considering the driver’s characteristics and traffic conditions using the driving data base. In addition, a relationship between the threshold power and various initial battery SOC was obtained by off-line optimization. The performance of the RBC was evaluated by simulation and human-in-the-loop simulation (HILS) for city driving. It was found from the simulation and HILS results that the RBC achieved approximately 4 % to 12 % reduction in fuel consumption compared to the existing charge depleting/charge sustaining (CD/CS) driving control. 相似文献
276.
G. C. Pereira M. M. F. Oliveira L. P. Andrade R. P Espíndola K. G. van Hecke N. F. F. Ebecken 《Journal of Marine Science and Technology》2016,21(4):651-662
Coastal zones are among the most productive areas in the world, offering a wide variety of valuable habitats and ecosystems services. Despite the low population density in the Brazilian coastal zone, their distribution is quite concentrated near some coastal cities and state capitals. This concentration places enormous pressure on coastal resources. Therefore, the main objective of this paper is to present an overview on the current status of SiMoCo (Sistema de Monitoramento Costeiro, or Coastal Monitoring System in English) project as a possible early warning system that can be integrated to the Brazilian Coastal Management Information System. This prototype platform provides a real-time access to the composition, organization and simulation of planktonic communities. First, our results demonstrate such a system detecting a target dinoflagellate; second, we apply structural and functional indexes to compare and characterize the ecological networks from two different coastal areas. Conclusions are made about SiMoCo’s feasibility and its possible contribution to the decision-making process within integrated coastal zone management (ICZM) strategies. 相似文献
277.
J. -S. Jo S. -H. You J. Y. Joeng K. I. Lee K. Yi 《International Journal of Automotive Technology》2008,9(5):571-576
The Vehicle stability control system is an active safety system designed to prevent accidents from occurring and to stabilize
dynamic maneuvers of a vehicle by generating an artificial yaw moment using differential brakes. In this paper, in order to
enhance vehicle steerability, lateral stability, and roll stability, each reference yaw rate is designed and combined into
a target yaw rate depending on the driving situation. A yaw rate controller is designed to track the target yaw rate based
on sliding mode control theory. To generate the total yaw moment required from the proposed yaw rate controller, each brake
pressure is properly distributed with effective control wheel decision. Estimators are developed to identify the roll angle
and body sideslip angle of a vehicle based on the simplified roll dynamics model and parameter adaptation approach. The performance
of the proposed vehicle stability control system and estimation algorithms is verified with simulation results and experimental
results. 相似文献
278.
Increasing fuel economy has been a central issue in the development of new cars, and one of the important strategies to improve
fuel economy is to decrease vehicle weight. In order to obtain this goal, researchers have sought to make bumpers lighter
without sacrificing strength, ability to absorb impact, or passenger safety. In this study, the effects of structural variables
on the torsional stiffness of a body bumper impact beam were analyzed for possible weight reduction. To this end, the effects
of variation of section height, increase of impact beam thickness and the addition of stays in a bumper impact beam were carefully
investigated and compared. Among these, the most effective way to increase the torsional stiffness of the bumper impact beam
was found to be increasing the section height. In addition, the potential for overall weight reduction of the impact beam
was examined by comparing the crash capability of a bumper using conventional steels with that of high-strength steel (boron
steel) with a tensile strength of 1.5 GPa. This analysis could serve as a guide to design for optimal bumper impact beam development. 相似文献
279.
S. J. Kim S. G. Kim K. S. Oh S. K. Lee 《International Journal of Automotive Technology》2008,9(6):703-711
The excitation force of a powertrain is one of major sources of interior noise in a vehicle. This paper presents a novel approach
to predict the interior noise caused by the vibration of the powertrain by using the hybrid TPA (transfer path analysis) method.
Although the traditional transfer path analysis (TPA) is useful for the identification of powertrain noise sources, it is
difficult to modify the structure of a powertrain by using experiments for the reduction of vibration and noise. In order
to solve this problem, the vibration of the powertrain in a vehicle is numerically analyzed by using the finite element method
(FEM). The vibration of the other parts of the vehicle is investigated by using experiments based on vibrato-acoustic transfer
function (VATF) analysis. These two methods are combined for the prediction of interior noise caused by a powertrain. Throughout
this research, two papers are presented. This paper presents a simulation of the excitation force of the powertrain exciting
the vehicle body based on numerical simulation. The other paper presents a prediction of interior noise based on the hybrid
TPA, which uses the VATF of the car body and the excitation force predicted in this paper. 相似文献
280.
Fatigue design approach for the spot-welded T-type member using a simulated single spot-welded joint
In order to develop a fatigue design method for actual railroad car and commercial vehicle body structures using the fatigue
data of simulated single spot-welded lap joints, we first analyzed the stress distribution and evaluated fatigue strength
of spot-welded T-type members that are the components of actual railroad car and commercial vehicle body structures. Next,
fatigue design approach of these members using the fatigue data of single spot-welded lap joints was investigated. From our
results, we found that, even though there was a quantitative difference of fatigue strength between the single spot-welded
joint and the actual members over the same number of fatigue cycles, through the use of appropriate correction, the fatigue
design criterion of actual spot-welded members, such as those used in railroad car and commercial vehicle body, can be predicted
using the fatigue strength of single spot-welded joint. 相似文献