基于单片机和车辆检测器的车型分析技术研究

车辆检测器的种类很多,检测方式和主要工作原理也各不相同,但车辆检测器都是基于车辆通过或存在,使检测器中能量发生变化而产生车辆感应信号。阐述地磁式车辆检测器的工作原理的,报告了国内外车型分类技术应用现状。进一步论述系统的硬件结构框图、基本功能及软件程序流程图,认为其应该是国内最有前途、最可能采用的一种车型自动分类技术。

公路弯沉检测替代车型优选应用研究

低等级公路建设中,路基路面弯沉是设计、交(竣)工时的重要参数,而只有贝克曼梁法检测弯沉指标才适用于现行规范。但是用来检测该指标的标准黄河车已停产,为找到替代车型,本文通过理论及实地测试,来分析相关车型能否替代标准车。

基于一般性人物评价方法的汽车造型审美评价层次研究

目的研究符合大众审美、对汽车销量有预见性的汽车造型审美评价理论。方法基于传统的汽车造型审美理论,将一般性人物评价方法的4个层次引入汽车造型审美评价理论,建立汽车造型审美评价的4个层次,即相貌、表情、气质和精神,并通过近年来的上市车型和部分概念车进行实证分析。结论得出了基于一般性人物评价方法的汽车造型审美评价层次,能够较好地对车型进行审美评价。

Mechanics analysis of vehicle bumping at approach slabs with superelevation

In order to analyze the pavement stress caused by vehicle bumping at an approach slab, a simplified four-wheeled bi- axle vehicle-moving model is proposed. The effect of damping and vibration reduction in the process of vehicle-moving is not considered. Based on the position change of vehicle wheels at the approach slab, the vehicle dynamic vibration equations are summarized. Meanwhile, the undetermined coefficients of the vibration equations are obtained using the boundary and initial conditions of the vehicle. The analytical motion solutions of rear and front wheels at different stages are concluded. Consequently, a four-wheeled vehicle model is developed and vibration equations are provided, which can be used to analyze the impact of complicated stress on pavement. The results show that the excessive stress and stress concentration will occur at the approach slab, and it needs to be strengthened.

Electromagnetic analysis and design of in-wheel motor of micro-electric vehicle based on Maxwell

To obtain a good drivability and high efficiency of the micro-electric vehicle, a new driving in-wheel motor design was analyzed and optimized. Maxwell software was used to build finite element simulation model of the driving in-wheel motor. The basic features and starting process were analyzed by field-circuit coupled finite element method. The internal complicated magnetic field distribution and dynamic performance simulation were obtained in different positions. No-load and load characteristics of the driving in-wheel motor was simulated, and the power consumption of materials was computed. The conformity of the final simulation results with the experimental data indicates that this method can be used to provide a theoretical basis to make further optimal design of this new driving in-wheel motor and its control system, so as to improve the starting torque and reduce torque ripple of the motor. This method can shorten the development cycle of in-wheel motors and save development costs, which has a wide range of engineering application value.

Noise Analysis of an Lightweight Auto-body Using FEM/BEM

Since numeric simulation can save much costs, it is widely used in autombile design. Besides, noise, vibration and harshness（NVH） performance is one major target for engineer to design a competitive product. In this paper, NVH performance of a lightweight auto-body prototype using alternative materials and gauge thickness were studied by finite element materials and boundary element method （BEM）. In order to fred the most contributing panel to the peak value of response, the panel acoustic contribution analysis （PACA） was performed and the most effective modification area was located. Finally, the sound pressure was reduced by putting damping material on these parts.

Benefit analysis of curb parking and study on its optimization model

Curb parking lot is a major part of city parking facility with lots of problems, especially in CCA (citycenter area and it has a lot of advantages and has much effect on dynamic traffic as well. It is therefore necessaryto control the scale of curb parking. Basing the whole benefits of the traffic system and considering the minimumsynthetical cost on curb parking, a optimization model is brought forward of cur. b parking planning in CCAbased on minimum generalized cost. Based on this model, the scale of curb parking can be defined reasonablyto make the whole benefits of traffic system optimum in CCA.

Analytical modeling and multi-objective optimization(MOO) of slippage for wheeled mobile robot(WMR) in rough terrain

Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots （AWMR） in rough terrain. A model and analysis of relationship among wheel slippage （S）, rotation angle （0）, sinkage （z） and wheel radius （r） are presented. It is found that wheel rotation angle, sinkage and radius have some influence on wheel slippage. A multi-objective optimization problem with slippage as utility function was formulated and solved in MATLAB. The results reveal the optimal values of wheel-terrain parameters required to achieve optimum slippage on dry sandy terrain. A method of slippage estimation for a five-wheeled mobile robot was presented through comparing the odometric measurements of the powered wheels with those of the fifth non-powered wheel. The experimental result shows that this method is feasible and can be used for online slippage estimation in a sandy terrain.

Numerical analysis on car-following traffic flow models with delay time

Effects of the speed relaxation time on the optimal velocity car-following model (OVM) with delay time due to driver reaction time proposed by Bando et al.(1995) were studied by numerical methods. Results showed that the OVM including the delay is not physically sensitive to the speed relaxation times. A modified car-following model is proposed to overcome the deficiency. Analyses of the linear stability of the modified model were conducted. It is shown that coexisting flows appear if the initial homogeneous headway of the traffic flow is between critical values. In addition, phase transitions occur on varying the initially homogeneous headway.

Fixture Variation Diagnosis of Compliant Assembly Using Sensitivity Matrix

An automotive body is composed of compliant sheet metal parts.Fast and exactly diagnosing variation sources is very important when assembly variations happen.This paper proposes a diagnosis method of multi fixture variations based on the variation model of compliant sheet metal assembly.The assembly variation model is obtained by using the method of influence coefficients(MIC) and considering the manufacturing variations of compliant parts and multi fixture variations.The measurement point variations induced by part manufacturing variations are firstly removed from the measurement data.The variation patterns of multi fixture variations are constructed by column vectors of fixture variation sensitivity matrix.This method is proved to be feasible for exactly diagnosing the fixture variations and has higher diagnosis efficiency than designated component analysis(DCA).

Evaluating Efficiency of Decision Making Units with Network Structures

This paper considers the problem of evaluating efficiency of Decision Making Units （DMUs） with network structures of divisions by the Data Envelopment Analysis （DEA） model. All divisions in the network are under a decentralized authority organiza- tion. That is, each division in a decision making unit has its own authority to adjust its input and output. By incorporating the division operations in the DEA model, we discuss the sufficient and necessary conditions for a DMU to be network efficient in series structure and general structure respectively.

Stability Analysis for Car Following Model Based on Control Theory

Stability analysis is one of the key issues in car-following theory. The stability analysis with Lyapunov function for the two velocity difference car-following model(for short, TVDM) is conducted and the control method to suppress traffic congestion is introduced. Numerical simulations are given and results are consistent with the theoretical analysis.