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701.
M. A. Eltantawie 《International Journal of Automotive Technology》2012,13(3):423-431
In this paper, a decentralized neuro-fuzzy controller has been created in order to improve the ride comfort and increase the
stability for half car suspension system, which used the magneto-rheological damper as a semi-active device. Firstly, relative
gain array and relative disturbance gain methods have been used for deriving a relation between inputs, disturbances and outputs
to select pairing with minimum interaction to design a decentralize controller. Secondary, decentralized neuro-fuzzy controllers
for front and rear chassis are designed to predict the required damping force taking the acceleration of the sprung mass and
desired acceleration obtained by using pole-placement method as inputs. To predict the control voltage required for producing
the force predicted by the controller, the inverse neuro-fuzzy model of MR damper has been designed. Simulation by using MATLAB
programs has been created. The results show that the ride comforts and vehicle stability have been improved in comparison
with the passive system. 相似文献
702.
703.
704.
A. Badea A. Furones F. J. Páez C. González 《International Journal of Automotive Technology》2010,11(5):711-720
Pedestrians are the most vulnerable users of public roads and represent one of the largest groups of road casualties; their
death rate around the world due to vehicle-pedestrian collisions is high and tending to rise. In Spain, as in other countries
of the European Union, steps have been taken to reduce the number and consequences of such accidents, with encouraging results
in recent years. A key to countering this concern is the accident research activity that has obtained remarkable achievements
in different fields, especially when multidisciplinary approaches are taken. This paper describes the development of a multivariate
model that is able to detect the most influential parameters on the consequences of vehicle-pedestrian collision and to quantify
their impact on pedestrian fatality risk. First, an accident database containing detailed information and parameters of vehicle-pedestrian
collisions in Madrid has been developed. The accidents were investigated on the spot by INSIA accident investigation teams
and analyzed using advanced reconstruction techniques. The model was then developed with two components: (1) a classification
tree that characterizes and selects the explanatory variables, identifying their interactions, and (2) a binary logistic regression
to quantify the influence of each variable and interaction resulting from the classification tree. The whole model represents
an important tool for identifying, quantifying and predicting the potential impact of measures aimed at reducing injuries
in vehicle-pedestrian collisions. 相似文献
705.
B. Suh A. Frank Y. J. Chung E. Y. Lee Y. H. Chang S. B. Han 《International Journal of Automotive Technology》2010,11(4):555-563
This research is the first to develop a design for a powertain system of a plug-in parallel diesel hybrid electric bus equipped
with a continuously variable transmission (CVT) and presents a new design paradigm of the plug-in hybrid electric bus (HEB).
The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in
HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV)
and to improve fuel economy and exhaust emissions of conventional bus and conventional HEBs. The control strategy of the complicated
connected propulsion system in the plug-in parallel HEB is one of the most significant factors in achieving higher fuel economy
and lower exhaust emissions of the HEV. In this research, a new optimal control strategy concept is proposed against existing
rule-based control strategies. The optimal powertrain control strategy is obtained through two steps of optimizations: tradeoff
optimization for emission control and energy flow optimization based on the instantaneous optimization technique. The proposed
powertrain control strategy has the flexibility to adapt to battery SOC, exhaust emission amount, classified driving pattern,
driving condition, and engine temperature. The objective of the optimal control strategy is to optimize the fuel consumption,
electricity use, and exhaust emissions proper to the performance targets. The proposed control strategy was simulated to prove
its validity by using analysis simulation tool ADVISOR (advanced vehicle simulator). 相似文献
706.
R. A. Sindhu M. K. Park S. J. Lee K. D. Lee 《International Journal of Automotive Technology》2010,11(6):857-863
This study was conducted to determine whether the different residual stresses caused by different welding speeds affect the
static and fatigue strength of laser-welded lap joints. Residual stresses in STS301L laser-welded lap joints of different
thicknesses under two laser-welding speed conditions, 4.1 m/min and 5.1 m/min, were evaluated with the incremental hole-drilling
strain gage method at the middle of the heat-affected zone (HAZ). Then, static and fatigue tests were performed. The results
show that higher static and fatigue strengths were obtained from the specimens welded with a 4.1 m/min welding speed than
from the specimens welded at 5.1 m/min. The main difference was due to the compressive principal residual stress magnitude
and its orientation near the HAZ. Also, the micro-hardness profile along the failure interface was measured to verify the
static and fatigue failure behavior. 相似文献
707.
A. Gauchia V. Diaz M. J. L. Boada B. L. Boada 《International Journal of Automotive Technology》2010,11(1):41-47
In this paper, the structural optimization of a real bus structure is proposed. The proposed optimization has been accomplished
by means of genetic algorithms. The structural behavior of the bus structure when subjected to weight and torsion was also
analyzed using the finite element method (FEM). The results demonstrate that improved weight and torsional stiffness are achieved
with the optimized structure. 相似文献
708.
Jorge A. Laval 《Transportation Research Part B: Methodological》2011,45(2):385-391
This paper presents new insights on the hysteresis phenomenon in congested freeway traffic. It is found that existing theories based on different driver behavior for acceleration and deceleration are incomplete. The data suggests that one needs to consider aggressive and timid driver behavior as well. These findings are based on an improved method for measuring traffic flow variables from trajectory data consistently with kinematic wave theory. 相似文献
709.
Pedro A.L. Abrantes Mark R. Wardman 《Transportation Research Part A: Policy and Practice》2011,45(1):1-17
Numerous travel demand studies have been carried out over the past five decades, many of which produce estimates of the value of travel time. This includes a rich body of largely unpublished evidence, which can provide valuable insights into the impact of variables such as GDP, travel distance, purpose and mode on this critical parameter for transport modelling and appraisal. The work reported in this paper updates and extends our previous meta-analyses of UK values of time (
[Wardman, 1998],
[Wardman, 2001a] and [Wardman, 2004]) by adding recent studies and widening the range of explanatory variables included. Our current research covers 226 studies carried out between 1960 and 2008, yielding a total of 1749 valuations (a 50% increase relative to our previous work) and making this the largest data set of its kind to the best of our knowledge. This is also the most comprehensive study to date of parameters other than in-vehicle time and includes valuations of walk, wait, headway, congested, free flow, late, departure time shift and search time. Exploratory analysis of the data set provides interesting insights into methodological trends in travel demand modelling.For each valuation, over thirty quantitative and categorical variables were recorded and then included in a multivariate regression model to explain variations in the value of time. A large number of statistically significant effects were obtained from this meta-analysis, some of which are in marked contrast with, or not present in, our previous work. One finding that stands out is that the estimated elasticity of the value of time with respect to GDP per capita is 0.9 and highly significant, a much closer correspondence to the widely used convention of a unit income elasticity over time than we have previously obtained. The ratio between walk and wait time and in-vehicle time was found to be substantially lower than the commonly used value of two. We also found large and significant differences between the results from studies based on different types of Stated Preference survey presentation. Other important effects include variations by mode used, mode valued, travel purpose, attribute type and distance. It is envisaged that the results are of direct relevance in the British context, as inputs to appraisal or for benchmarking, whilst the methodological implications are of broader interest and the results, in terms of time equivalents and variations in values of time, can be transferred to other contexts. 相似文献
710.
The aim of this paper is to propose a model for the design of a robust rapid transit network. In this paper, a network is said to be robust when the effect of disruption on total trip coverage is minimized. The proposed model is constrained by three different kinds of flow conditions. These constraints will yield a network that provides several alternative routes for given origin–destination pairs, therefore increasing robustness. The paper includes computational experiments which show how the introduction of robustness influences network design. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献