Seok-Won Kang

Design of PRT operating system based interlocking between virtual and real environment

Unlike existing general railways, PRT system is the new urban transit system which is operated non-stop to the destination of passengers on an on-demand basis by being operated in the method of off-line station based on operation lines in the form of complex networks. This PRT system is the new means of transportation that was proposed conceptually long time ago and is being test-operated at some sites in some foreign countries currently. In Korea also, studies on this PRT system which is the new means of transportation with a new concept were started, and this paper explains contents of design on operation system of PRT system as one of them. Especially, this paper explains contents of design on PRT operation control system through linkage of virtual environment to the real environment in accordance with the impossibility of securing physical spaces and manufacturing multiple vehicles in developing the new means of transportation.

Development of an Operation Control System of the Vertical Transferable Korean Personal Rapid Transit

The PRT(Personal Rapid Transit) in material or immaterial guided tracks is operated automatically according to the needs of passengers with the optimal non-stop path from the source to the destination. In recent years, the personal rapid transit (PRT) system, which affords superior accessibility and ease of use, has been spotlighted as a new transport system for the future. In this study, a method for vertical lifting of PRT vehicles was proposed to facilitate interlink with other means of transport and thereby improve the efficiency of door-to-door transport. For this purpose, operation control interfaces were designed and experiments were conducted. Programmable Logic Controller (PLC) dedicated for the PRT vertical lift was designed to interface with Operation Control Center (OCC) by Modbus TCP over Ethernet. We implemented a 3D graphical PRT operation simulator which can emulate the mixing operation of the virtual vehicles and the actual vehicles.

Complement of the Interlocking Logic of ATS for Heterogenous Railway Signaling Systems

The railway signaling system has evolved to maximize its safety and maintainability based on the experiences in the construction and operation of railway systems. The newly developed systems was established to cope with the changes in an operating environment. In the process of a transition to the new system, both the existing ATS (Automatic Train Stop) and new ATP/ATO (Automatic Train Protection/Automatic Train Operation) systems are operating simultaneously in parallel. In this situation, modifications of the conditions of the interlocking diagram and logic are necessarily required on the existing ATS systems due to the frequent improvements in signaling equipment. This paper reports the enhancement of safety and operational efficiency of the system through an improvement of the security and the interlocking conditions of the existing ATS systems. The independent display of signals for each track was ensured to avoid giving the effect of On/Off signals for the selected track on the opposite side, and the security was improved by adjusting the position and interlocking conditions. In addition, the increased traffic density of railway systems was achieved by removing the unnecessary conditions and detailed signal display, which resulted in enhanced operational efficiency

Investigation of Convective Heat Transfer Characteristics of Aqueous SiO 2 Nanofluids under Laminar Flow Conditions

The effect of the migration of nanoparticles near the wall of a channel on the convective heat transfer in a laminar flow of SiO2 nanoparticle suspensions (nanofluids) under constant wall heat flux boundary conditions was numerically and experimentally investigated in this study. The dynamic thermal conductivity of the aqueous SiO2 nanofluids was measured using T-type thermocouples attached to the outer surface of a stainless steel circular tube (with a length of 1 m and diameter of 1.75 mm). The nanofluids used in this study were synthesized by dispersing SiO2 spherical nanoparticles with a diameter of 24 nm in de-ionized water (DIW). The enhancement of the thermal conductivity of the nanofluids (e.g., an increase of up to 7.9 %) was demonstrated by comparing the temperature profiles in the flow of the nanofluids with that in the flow of the basefluids (i.e., DIW). However, this trend was not demonstrated in the computational analysis, because the numerical models were based on continuum assumptions and flow features involving nanoparticles in a stable colloidal solution. Thus, to explore the non-continuum effects, such as the modification of the morphology caused by nanoparticle-wall interactions on the heat exchanging surfaces (e.g., the isolated and dispersed precipitation of the nanoparticles), additional experiments were performed using DIW right after the measurements using the nanofluids.

Structural Strength Evaluation for Development of a Vertical Transfer Device for a Personal Rapid Transit (PRT) Vehicle

Abstract : This paper presents numerical results of static structural stability analysis in development of a vertical transfer device of a PRT(Personal Rapid Transit) vehicle. The vertical transfer of a fully occupied vehicle operating on a road network is the first attempt, which is expected to contribute to overcome the limitations of conventional 2-dimensional operation mode. In particular, the vertical transfer apparatus designed based on vertical circulating conveyors is capable of continuous transfer without time delay so that it enables to accommodate a high traffic density. This system has been frequently used in a logistics field; however, it is essential to assess a structural integrity because an external force by a vehicle weight is exerted on the conveyors in the form of a concentrated load unlike a conventional logistic transport. In this study, prior to the production process, the structural performance of the pilot design in an early stage is numerically evaluated using the commercial finite element method (FEM) solver (i.e., Ansys

Magnetic Markers-based Autonomous Navigation System for a Personal Rapid Transit (PRT) Vehicle

Recently, the demand for a PRT(Personal Rapid Transit) system based on autonomous navigation is increasing. Accordingly, the applicability investigations of the PRT system on rail tracks or roadways have been widely studied. In the case of unmanned vehicle operations without physical guideways on roadways, to monitor the position of the vehicle in real time is very important for stable, robust and reliable guidance of an autonomous vehicle. The Global Positioning System (GPS) has been commercially used for vehicle positioning. However, it cannot be applied in environments as tunnels or interiors of buildings. The PRT navigation system based on magnetic markers reference sensing that can overcome these environmental restrictions and the vehicle dynamics model for its H/W configuration are presented in this study. In addition, the design of a control S/W dedicated for unmanned operation of a PRT vehicle and its prototype implementation for experimental validation on a pilot network were successfully achieved.

A Study on Optimal Horizontal Alignment Design for PRT Vehicle

Personal rapid transit(PRT) systems have been highlighted in future transportation developments as a result of their potential as sustainable and eco-friendly transport solutions that provide demand-responsive mobility services. One of the most important characteristics of the personal rapid transit system(PRT) is that it can be constructed and operated at a low cost. A fundamental study on the alignment of the PRT guideway considering running stability was conducted in the present study. In addition, a parameter analysis of the major alignment design variables such as curve radius, transition curve length and cant was performed by vehicle dynamic analysis and optimum guideway alignments were proposed. The analysis results suggested that the theoretical values were satisfied and also confirmed the possibility of reducing the standard.

Design and Implementation of Wireless Power Transfer System for a Personal Rapid Transit (PRT) Vehicle

Abstract Recently, the traditional paradigm in railroad technology is changing as more efficient and cost- effective electric vehicle (EV) technologies have emerged. The original concept of PRT (Personal Rapid Transit) proposed in the past has come to be regarded as unrealistic, but its feasibility is improving through the utilization of an EV platform. In particular, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. However, based on the inductive power transfer (IPT) technology, the fast charging of supercapacitors with high energy density can contribute to overcoming this technical challenge and promote the transition to electric-powered ground transportation by improving the appearance of cities. This study discusses the development process of a power supply system for PRT, including concept design, numerical analysis, and device manufacturing, along with performance predictions and evaluations. In terms of results, the system was found to meet the performance requirements for power supply modules on a test-bed.

Operation scenario on passenger car calling for Personal Rapid Transit

The PRT(Personal Rapid Transit) system is a new transportation service system which has fixed schedule and along the root system in accordance with the requirements of the passengers. The PRT system are being developed and applied on a pilot basis to demonstrate the concept of PRT system in some areas overseas but this new transportation system is in the early stages of development at Korea and abroad, especially in the unclearly operational aspects. The operation related studied of these new transportation transit system has begun in Korea. As one of these studies, this paper describes the interface protocol for the ability to call the vehicle by the passenger when arrived at station.