• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.10
• /
• pp.1770-1774
• /
• 2007

In this paper we deal with a design of the evaluation system to assess the vehicle operational control algorithm for Personal Rapid Transit(PRT) system. PRT system is different from the conventional rail traffic system in such that the station is off-line so as to guarantee a very short headway. In this study we propose an evaluation system to assess the performance of the proposed vehicle control algorithm. The evaluation system is composed of virtual vehicles, central control system, virtual wayside facilities, monitoring equipments. The virtual vehicles are made up by the laptop computers and the central control system employs Power PC process of Motorola Inc. The wayside facilities are implemented by employing the PXI module of the National Instruments Corporation. In order to test the proposed evaluation system a test algorithm is used, which has been simulated in the combined simulation system between Labview Simulation Interface Toolkit and Matlab/Simulink.

• Proceedings of the KIEE Conference
• /
• 2003.10b
• /
• pp.283-285
• /
• 2003

Metro is taking an important part as a public transportation of densely populated area. but according to request of increasing transportation demand and improving service for passengers, minimizing headway, functional improvement of safety facility, improving riding comfort are needed. Also, it is the time for Seoul metro's signalling system to be improved into a new one as it has been opened to traffic for over 20 years and its signalling system is becoming superannuated. this paper reviewed the considerations at improving a signalling system and its solution.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.1069-1070
• /
• 2006

This study is concerned with the control system design using Labview Simulation Interface Toolkit and Matlab/simulink combined system for an application to the personal rapid transit system which has very short headway, requiring accurate speed control to avoid the impact between the vehicles. A simple equation of motion for a vehicle which is activated on the linear motor is introduced. A speed profile that should be tracked by a rear vehicle is produced based on the state information of the two vehicles(the preceding vehicle and the rear vehicle). The speed profile tracking control system is designed by Matlab/simulink. The simulation results show that the proposed control system is effective to evaluate the speed tracking performance.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.216-222
• /
• 2003

Train control by radio based communication is one of the interesting new fields in train signal. The radio based control has more benefits, low headway and low construction and maintenance cost, than conventional control. In this paper, a safe and efficient train operation is introduced. Triple radio communications, train to train, train to station, and train to central traffic control, are used to increase the reliability. One of these communications channels has a fault; the others can take the functions of it. Absolute position of a train is transmitted to station via radio communication. In the station, the interlocking mechanism should be activated as the legacy.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.717-722
• /
• 2003

A driving simulator is a computer-controlled tool to study an interface between a driver and vehicle response by enabling the driver to participate in judging vehicle characteristics. Using the driving simulator, human factor study, vehicle system development and other research can be effectively done under controllable, reproducible and non-dangerous conditions. An Adaptive Cruise Control (ACC) system is generally regarded as a system that can be achieved in the near future without the demanding infrastructure components and technologies. ACC system is an automatic vehicle following system with no human engagement in the longitudinal vehicle direction. And the influence of the driver is substantial in developing the system. Driving characteristic is very different according to the accident riskiness, gender, age and so on. In this research, experiments have been carried out to investigate driving characteristics with the ACC system, using a driving simulator. Participants are 21 male and 19 female. Driving characteristics such as preferred headway-time, lane keeping ability, eye direction, and head movement have been observed and compared between the driving with ACC and the driving without ACC.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.8
• /
• pp.907-913
• /
• 1999

For an automated transportation system like PRT(Personal Rapid Transit) system or IVHS, an efficient vehicle-merging algorithm is required for smooth operation of the network. For management of merging, collision avoidance between vehicles, ride comfort, and the effect on traffic should be considered. This paper proposes an unmanned vehicle-merging algorithm that consists of two procedures. First, a longitudinal control algorithm is designed to keep a safe headway between vehicles in a single lane. Secondly, 'vacant slot and ghost vehicle' concept is introduced and a decision algorithm is designed to determine the sequence of vehicles entering a converging section considering energy consumption, ride comfort, and total traffic flow. The sequencing algorithm is based on fuzzy rules and the membership functions are determined first by an intuitive method and then trained by a learning method using a neural network. The vehicle-merging algorithm is shown to be effective through simulations based on a PRT model.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.56-58
• /
• 2005

This paper for the Train control system which has been used in the railway system for the purpose of headway control is regarded as safety-critical system, which is based on embedded controller. Therefore, for the maintainability, the maintenance time shall be predicted correctly in order to improve availability of railway system and the predictive values shall be proved through the test. In conclusion, for the maintainability of train control system, the solution for exact prediction based on related international standard and the system for justification of derived predictive values shall be proposed.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1191-1192
• /
• 2007

In this paper we deal with a design of the evaluation system to assess the vehicle operational control algorithm for Personal Rapid Transit(PRT) system. PRT system is different from the conventional rail traffic system in such point that the station is off-line so as to guarantee a very short headway. In this study we propose a evaluation system to assess the performance of the proposed vehicle control algorithm. The evaluation system is composed of virtual vehicles, central control system, virtual wayside facilities, monitoring equipments. In order to test the proposed evaluation system a test algorithm is used, which has been simulated in the combined simulation system between Labview Simulation Interface Toolkit and Matlab/Simulink.

• Journal of Korean Society of Transportation
• /
• v.23 no.3 s.81
• /
• pp.137-147
• /
• 2005

This study is to define new road capacity concept, and to develop and propose an estimation method, through the analysis of individual vehicular behaviors in continuum flow. Developments in detection technology enable various and precise traffic data collection. The U.S. HCM (Highway Capacity Manual) method does not require such various and precise traffic data, and outputs only limited results. Alternative capacity concepts, which can be classified into a stochastic model and behavioral or deterministic model, are attempts for modeling some prominent traffic flow features, namely so-called a capacity drop and a traffic hysteresis, using such various and precise traffic data. Yet, no capacity concept up-to-date can describe both features. The analysis of individual vehicular behaviors, including speed-density plot per time lap, traffic flow-speed-density diagram per each sampling interval, time headway distribution, and free flow speed distribution, is performed for overcoming the limits of the previous capacity concepts. A stochastic methods are applied to determine time headway for estimating freeway capacity for traffic control.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.438-442
• /
• 2003

For an efficient sliding mode control system stability and chattering avoidance should be guaranteed. A continuation method using boundary layer is well known as one solution for this. However since not only model uncertainties and disturbances but also control task itself is variable. it is practically impossible to set controller parameters - control discontinuity, control bandwidth, boundary layer thickness - in advance. In this paper first an adaptation law of control discontinuity is introduced to assure system stability and then fuzzy logic based tuning algorithm of design parameters is applied based on monitored performance indices of tracking error, control chattering, and model precision. In the end maximum control bandwidth not exciting unmodeled dynamics and minimum control discontinuity, boundary layer thickness making system stable and free of chattering are found respectively. This eliminates control chattering and enhances control accuracy as much as possible under given control situation. In order to demonstrate the validity of the proposed algorithm safe headway maintenance control for autonomous transportation system is simulated. The control results show that the proposed algorithm guarantees system stability all the time and tunes control parameters consistently and in consequence implements an efficient control in terms of both accuracy and actuator chattering.