Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 4 Articles
Although the private carpooling market of China has grown rapidly, it has been embarrassed by problems such as obstructed\ninformation, disordered expense, and frequent crimes currently. In this paper, a commute carpooling program based on fixed time\nand routes is designed and corresponding carpooling information platform is built to realize information retrieval, information\nmatching, and mutual selection and evaluation. We have practiced the program in Huaian, China, and then evaluated it using\nthe improved time-expense impedance model and VISSIM simulation system. The result shows that the carpooling program can\nreduce 65%?86% of the time-expense impedance and optimize some network parameters up to 20%?40%. Since it will help in\nreducing the travel time and cost greatly, improving safety and economy during carpooling, and easing the traffic congestion, it is\na worthy carpooling mode to be extended in China....
This paper presents a formulation and procedure for incorporating the multibody dynamics analysis capability of\ntracked vehicles in large-scale multibody system. The proposed self-contained modular approach could be interfaced to\nany existing multibody simulation code without need to alter the existing solver architecture. Each track is modeled as a\nsuper-component that can be treated separate from the main system. The super-component can be efficiently used in\nparallel processing environment to reduce the simulation time. In the super-component, each track-link is modeled as\nseparate body with full 6 degrees of freedom (DoF). To improve the solution stability and efficiency, the joints between\ntrack links are modeled as complaint connection. The spatial algebra operator is used to express the motion quantities\nand develop the link�s nonlinear kinematic and dynamic equations of motion. The super-component interacts with the\nmain system through contact forces between the track links and the driving sprocket, the support rollers and the idlers\nusing self-contained force modules. Also, the super-component models the interaction with the terrain through force\nmodule that is flexible to include different track-soil models, different terrain geometries, and different soil properties.\nThe interaction forces are expressed in the Cartesian system, applied to the link�s equation of motion and the\ncorresponding bodies in the main system. For sake of completeness, this paper presents dynamic equations of motion of\nthe links as well as the main system formulated using joint coordinates approach....
The effects of bullet vehicle crash impact angle, child restraint system design, and restraint harness slack at side impact speed of\n32.2 km/h (20mph) on moments sustained at the neck by a three-year-old child are investigated. Mathematical models are built\nusing the response surface method based on simulation results whereby good fitness is achieved. The singular and cross interactive\neffect of each predictor on the neck moment are analyzed. The number of significant parameters affecting the neck moment is\nshown to be the largest for wide impact angles (???? ? 60? ) and the impact angle parameter is largely revealed to be themost sensitive.\nAn ideal safe range for low neck moment has been established to be within ???? angles 45? and 65?. It is further shown that the nature\nof all parameters effect on the neck moment is highly dependent on the impact angle range....
Traction control is an important element in modern vehicles to enhance drive efficiency, safety, and stability. Traction is produced\nby friction between tire and road, which is a nonlinear function of wheel slip. In this paper, a sliding-mode control approach is used\nto design a robust traction controller.The control objective is to operate vehicles such that a desired wheel slip ratio is achieved. A\nnonlinearity observer is employed to estimate tire tractive forces, which are used in the control law. Simulation and experimental\nresults have illustrated the success of the proposed observer-based controller....
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