| Based on the national natural science fund project of "Model and method on socio-economic impact measurement for ITS projects" (50178033), combined with the status of ring freeway of Changchun, this paper makes deep research on the on-ramp control system of freeway, and also makes deep exploration on the application of related simulation model on the assessment of ramp control system control algorithm. Having an investigation on link traffic flow of typical place of Changchun ring freeway, on the basis of investigation data, the paper makes calibration. The simulation index of ramp-metering control system can be divided into two kinds, the efficiency and equity. Make equilibrium of the two indexes by using linear programming method, in order to choose the optimizing control project of diversified traffic flow under different weight ratio.Transportation is a general and guiding basic industry in national economy, as the fundamental facilities of modern transportation, freeway has become the skeleton transport mode and important channels with its remarkable characteristic of big capacity and high velocity. The traffic control of freeway is the important sign of improvement level of freeway. So, the research on ramp-metering control system can improve the freeway control system of our country.In recent years, the traffic volume of freeway has increased promptly, and this results in the increase of traffic jam and accident. These days, many freeways adopt ITS to decrease jam and guarantee the safe, fast and high-efficient operation. Some countries in USA and Europe, as the subsystem of ITS, ramp-metering controlsystem of freeway have been widely used. Its basic purpose is to control the traffic demand of freeway, with the traffic flow of freeway masterstroke as the controlling object, and the flow of on-ramp as the input data of the system, through calculating the balance between the traffic demand of upriver and the road capacity of downriver to find the optimal control of on-ramp volume, and then makes the traffic demand of the freeway itself less than its capacity, keeps the traffic flow of freeway masterstroke in optimal status.Then, before entering freeway, some vehicles that look forward to use the freeway should be asked to wait at the on-ramp. If they don't want to wait at the on-ramp, they can choose not to use freeway or to reenter at another time. The result of controlling on-ramp is to transfer the delay factors to the on-ramp, consequently, to keep the traffic flow not interrupted and not crowded either, that is, to transfer the superfluous vehicles to another road which is exchangeable, or to choose another time which demand is low, or to adopt other transportation modes.Just based on the idea that is mentioned above, this paper launches further investigating. This paper can be divided into seven chapters and expounds key technique that is mentioned above during the simulation research of freeway ramp-metering control system, the main ideas in this paper are shown as follows:Chapter â… Introduction. At first, this chapter discusses the background of thesis and the necessity of research, explains the internal and external status of ramp control algorithm and the existing problem, and then introduces the main contents of this paper.Chapter â…¡ Review of ramp control research. This chapter introduces principles and system composing of on-ramp control system, and also the common algorithm of on-ramp control.Chapter â…¢ Characteristics of freeway traffic flow. Roadway traffic characteristic, driver-vehicle-road characteristic, traffic flow characteristic, operation characteristics of vehicles on freeway masterstroke and on freeway ramp are introduced in this chapter, so that theoretical basis of traffic flow simulation research is offered.Chapter â…£ Development of microscopic simulation models. Programdesign of car-starting model, car-following model, lane-changing and car-running model are discussed detailedly, suited model is chosen to complete the computer simulation program design of ramp-metering system, simulation instrument is offered to the selection of optimal control project of ramp-metering system and based on the typical place: ring freeway of Changchun, traffic data is investigated, and simulation model is calibrated, this offers basic data of traffic flow for on-ramp control system simulation on typical place.Chapter â…¤ Traffic simulation evaluation of ramp-metering. This chapter gives a design about on-ramp control system of Changchun ring freeway and makes computer simulation. On the basis of simulation data, equity principle should be considered into the research of on-ramp control algorithm, so that, it can improve users' satisfaction, this chapter also gives a new idea about using Gini coefficient to reflect equity status about users. Combined with two incompatible indexes efficiency and equity, linear programming method is put forward to harmonize different weight ratio compared with efficiency and equity, and according to each traffic flow, optimal control ratio is chosen.Chapter â…¥ Simulation and analysis of integrated control system of on-ramp and variable speed limits. Control theory of variable speed limits is introduced in this chapter, combined on-ramp control system with variable speed limits, integrated control system is formed to control traffic flow. Based on simulation data, making equilibrium by the principle of efficiency and equity, two side indexes are harmonized by using linear programming. Under different traffic volume, the optimal control project is chosen for different weight ratio, this makes integrated control system run better.Chapter â…¦ Summarization and the prospect. Summarize the main conclusions of this paper, and then point out the question that will be studied further in the future.The innovation of this paper is shown as follows:(1) Gini coefficient of economics is introduced into the evaluation of on-ramp control, the value of Gini coefficient is the equity index of system, trip time and speed standard deviate are applied as efficient index, the index which is put...
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