Advanced Materials Research Vols. 299-300

Abstract: Kinematics simulation model of double wishbone independent suspension of a car made in China was established based on ADAMS, and the curves of the alignment parameters of the suspension were analyzed. Aiming at the toe angle changed widely, taking the minimum variation of the wheel alignment parameters and sideway displacement as optimization goal, the multi-objective optimization of the suspension was calculated by using ADAMS/Insight. The simulation results showed the variation of toe angle reduced greatly, the performance of the suspension was improved to some extent, achieving the aim to optimization.

Abstract: In the present study, the interaction effects of different vehicle speeds and vehicular exhaust tailpipe exit velocity conditions on the exhaust particle dynamic behaviors in the near-wake region behind the studied vehicle were numerically investigated. The results showed that the particles were drawn up into the recirculation region and then moved toward into the upper vortex by its lower vortex. A lower particle number concentration behind the studied vehicle is observed for a higher vehicle speed because of the rapidly increasing dilution ratio and the nucleation rate. The particle volume concentration is the highest in the recirculation region behind the studied vehicle and is diluted gradually beyond the recirculation region in the downstream.

Abstract: This paper discusses pseudo excitation method and constructs pseudo six-wheel pseudo excitation. For the complexity of heavy-duty truck, construction of vibration model is difficult for real structures; thirteen-degree-of-freedom full model is constructed for heavy-duty truck. Taken frequency response function as a bridge, pseudo excitation method is applied and a new method is gained for statistical characteristics of heavy-duty truck. The result shows that the method for random vibration of heavy-duty truck is feasible and convenient by constructing six-wheel road pseudo excitation and obtaining power spectral densities of vibration responses.

Abstract: The point clouds data of auto outer door panel is measured with CMM. After data processing and extracting of contour line feature, the surface is reconstructed in CATIA software. With the example, the process of reverse design how to acquire CAD model of product from actual object or sample is studied.

Abstract: Supplier evaluation and selection is one of the most important components of supply chain, which influence the long term commitments and performance of the plant. Supplier selection is a complex multi-criteria problem which includes both qualitative and quantitative factors. In order to select the best suppliers it is essential to make a trade off between these tangible and intangible factors some of which may conflict. In this paper, an AHP-based supplier selection model is formulated and then applied to a real case study for a polyamide fiber plant in China. The use of the proposed model indicates that it can be applied to improve and assist decision making to resolve the supplier selection problem in choosing the optimal supplier combination.

Abstract: In this paper, a cybernetic model of “driver-vehicle-road” closed-loop system including a driver model and a steering system model is built under the MATLAB/Simulink environment. Then, the influence of different dynamic characteristics of steering system on vehicle handling and stability is studied. The results suggest that the “driver-vehicle” model built has a high tracking precision in following the path; Increasing the rigidity of steering system or decreasing the dilatory distance of front tire can enhance the tracking precision and can minish the driving burden and the fatalness of side-tip, the total evaluation result of vehicle performance will be optimized as well.

Abstract: Having set up the mechanical structure motive reliability functional equation with random load. The reliability can be worked out using the second-matrix and perturbation methods. At the same time, the variation regularity of the mechanical structure strength, load, reliability and the failure rate have been studied. It indicates that when the strength decreases, the reliability of mechanical structure inclines slowly with time increasing, and the failure rate increases at the same time, and it has the feature of the later period of a "bath tub "curve. Using a specific example the motive curve of reliability and the failure rate with time changing can be obtained. They have certain guiding significance for determining test time and reliable life of components.

Abstract: The 15 degrees of nonlinear dynamic vehicle model is established, and then Dugoff and magic formula tire model are studied by comparison. Then the braking system dynamics model and the side-slip angle estimation algorithm are discussed. Stability control system is established based on the control target of combined yaw and side-slip angle with linear 2-dof vehicle handling characteristics model. It shows that control system can perfectly control vehicle driving and can improve the stability of car active safety through the serpent’s simulation test.

Abstract: As the uncertain characteristics of traffic flow in urban expressway, fuzzy control can be used as an effectual way to solve traffic problem. A fuzzy controller of signal intersection is designed for alleviating traffic congestion downstream off-ramp at the Surface Street. The overtime of green-light and the next time for green-light phase are optimized according to the queue lengths and the numbers of phase delay, and the method corresponds to a man’s decision-making process. Simulation research based on MATLAB program design is carried out and the results show that the methods are promising and the fuzzy controller have a better performance for congestion mitigation downstream off-ramp of urban expressway.

Abstract: Bike rental is an important traffic mode under the low-carbon mode. Bike rental pricing is the key technology of the bike rental. In the paper, bike rental pricing model is researched. Firstly, the influential factors of the bike rental pricing are analyzed, such as cost, demand, rental location, time, depreciation rates, government policy, competition conditions, income level, psychological pricing, the other public transport pricing situation and so on. Secondly, the average-cost pricing and the Logit model are combined, and the pricing model is established by considering the depreciation rate, the distribution rate, the ratio of the travel time and the rental time. Finally, the model is solved. According to time, rental location and bike models, the price of bike rental and the appropriate deposit of bike can be determined by using this model.