Platform Screen Door System Research Articles

Improvement of Platform Screen Door System - Focus on inability to automatically open PSD -

Improvement of Platform Screen Door System - Focus on inability to automatically open PSD -

Numerical Study on the Impact of Platform Screen Doors in a Subway Station with a Train on Fire

Almost all recently built subway stations are equipped with Platform Screen Doors (PSDs) due to the numerous proven benefits of these systems. In addition, PSDs are now being introduced in existing subway stations, but their operation in conjunction with previously designed ventilation systems in case of emergency should be deeply studied. In this context, the objective of this study is to assess the efficiency of the planned emergency strategy (coupled operation, ventilation systems–PSDs system) in the case of trains on fire stopped at the platform of a subway station retrofitted with PSDs. The approach is based on Computational Fluid Dynamics (CFD) full-scale simulations to predict the airflow, temperature, and pollutant (carbon monoxide—CO and carbon dioxide—CO2) concentrations caused by the fire. The results show the evident contribution of PSDs in stopping the dispersion of hot and polluted air in the subway station during the entire simulation time (20 min from the arrival of the train on fire). Consequently, the investigated emergency strategy (exhausting air both through the “over track system” and the “under platform system”, simultaneously with the opening of the PSDs on the side with the train on fire) assures the safe evacuation of passengers as soon as they have left the subway train. The results indicate that access to the platform is not perturbed by high temperatures or dangerous concentrations of CO and CO2.

Energy benchmarking analysis of subway station with platform screen door system in China

The energy consumption of Ventilation and Air Conditioning (VAC) systems in subway stations has attracted much attention, aiming to figure out energy-saving potentials and improve energy efficiency. Benchmarking is a useful method to evaluate energy performance of VAC systems during the operational stage. This study describes the development of an energy benchmarking model for the analysis of VAC energy consumption in subway stations with platform screen door systems in a variety of climate regions in China. Firstly, the Constraint Value (CV) and Leading Value (LV) of VAC energy use were simulated using a validated theoretical energy model, which represent the “general” and “superior” level of the VAC energy use, respectively. Results show that, for the 2,520 simulated cases, CV ranges from 184 to 859 × 103 kWh/year and LV ranges from 178 to 529 × 103 kWh/year, with different ranges for cold, hot-summer cold-winter, and hot-summer warm-winter region. Next, the simulated values of CV and LV were applied to establish an energy benchmarking model using the ordinary least square approach. For each climate region, the regressive energy benchmarking models for CV and LV were established and validated by cross-validation. Results show that R2 are 0.753–0.903 and MBE of the test set are 2.1–7.1%, indicating a good fit for the regressive benchmarking models. In order to further test their application, the regressive models were then applied to existing subway stations. Finally, the impacts of service-related variables, i.e. number of passengers, train departure density, and tunnel length, on the CV and LV were discussed. The proposed energy benchmarking model and analysis provide a convenient and effective tool for operators and managers to evaluate VAC energy consumption status and assess energy-saving potentials for subway stations.

Characteristics of subway air quality and favorable locations for passengers waiting and taking the subway

With the increase of commuters in Beijing subway, the air quality inside subway systems has caused widespread apprehension. The particulate matter (PM) level and potential health risk of PM on the platforms and carriages of Open (O) system, Half-height platform door (HPD) system, Full-height platform door (FPD) system, Platform screen door (PSD) system were studied. The average PM2.5 concentration was approximately twice the Chinese National Ambient Air Quality Standard Class II threshold and ten times the WHO Global Air Quality Guidelines. The average PM2.5 and PM10 ratios on the platform and inside carriages were 0.81 and 0.85, respectively. Compared to the FPD and HPD, the PSD has the highest ability to prevent tunnel dust entering the platform, whereas, the FPD's preventive ability is insignificant. The maximum comprehensive indoor-air quality index (CIAI) values for platform PM2.5 and PM10 are at a very unhealthy risk level and unhealthy risk level, respectively. The average PM2.5 doses deposited by adult males in extrathoracic (ET), tracheobronchial (TB) and alveolar-interstitial (AI) during a day's round-trip ride were 163.7 μg, 9.6 μg and 24.1 μg, respectively. The PM concentration at the station platform nearer to the entrance location is greater than the middle of the platform and the center of the station hall. The PM concentration at the middle of the carriage between two doors is lower than that at the door. The research results have important guidance for constructing a subway environmental control system, station passenger flow command desk setting, passenger waiting and taking the subway to reduce the health risk.

Flatness Measurement of Platform Screen System Welding Assembly Using Stereo Vision and Grid Pattern Projector

The welding assemblies are the main components of the platform screen door system, which can offer the subway with safety, economy, and silence. The deformed welding assemblies can reduce the carrying capacity of the platform screen door system, so the flatness needs to be measured before installation. In this study, a flatness measuring robot based on stereo vision and grid pattern projector measuring system is developed to online measure the welding assembly flatness in workshop. The developed robot is capable of measuring the flatness by incorporating the following solutions: 1) measuring system consisting of stereo vision and grid pattern projector is designed; 2) grid intersection location method using grid intersection probability calculation, candidate preselection, grid intersection reexamination and sub-pixel refinement is proposed, which can consider both false positives and false negatives by using preselection-and-reexamination; 3) 3D coordinates of sampling points (grid intersection) are calculated based on stereo camera calibration and robot hand-eye calibration; 4) flatness measuring method based on the least squares plan is employed to calculate the flatness of welding assembly. The developed flatness measuring robot is robust, accurate, and efficient, as demonstrated by the following performances: an average measuring bias of 0.10 mm in actual working conditions, and an average measurement time of 4.1 s for single welding assembly, meeting the engineering requirements. It is foreseeable that the developed flatness measuring robot has great application market in the online measurement with a middling accuracy and high efficiency.

Piston wind characteristic and energy saving of metro station environmental control system

Energy-saving is conductive to sustainable development. However, metro environmental control system accounts for great energy consumption in subway system. This paper focused on the effective utilization of unorganized fresh air induced by piston effect in the transitional season, aiming to save energy of ventilation system in metro station, and the method of combining numerical simulation with experiment was used. Firstly, the validity of numerical model was verified by comparing with experimental data. Secondly, the operation mode of environmental control system in metro station was reasonably scheduled, and the energy saving of ventilation system of metro station in the cities with different climate was calculated. The results show that the new environmental control system has the potential to save energy compared with traditional platform screen doors system. In some cities of temperate zone, the maximum energy saving is 75890 kW h of electricity every year. The maximum rate of energy saving is 42.71% with remarkable energy saving effect. The energy saving potential in other climates is limited, especially in cold zone, where the minimum energy saving is merely 23759 kW h of electricity every year, and the minimum rate of energy saving is only 9.67%. Besides, the results also indicate that unorganized fresh air flowing into the station is mainly caused by the suction effect of the moving train, which could be well applied to the design of environmental control system of metro station and provide a theoretical basis for utilization of unorganized fresh air induced by piston effect.

Research on remaining service life prediction of platform screen doors system based on genetic algorithm to optimise BP neural network

ABSTRACT The platform screen door system related to the safety of passengers, vehicle and station operation in rail transit is the research object. Relay, the key component of the PSD system, is selected as the breakthrough point, and the number of pull-in is used as the evaluation index of the service life of the relay. The precise and complex mapping between the influencing factors of the relay (coil resistance, pull-in voltage, release voltage, pull-in time, release time and contact resistance) and the remaining service life of the PSD system are established based on genetic algorithm to optimise BP neural network, and a new model for predicting the remaining life of the PSD is constructed. The PSD system of Guangzhou Metro Line 8 – KeCun Station is taken as the experimental test object. By comparing the BP algorithm, the PSO-BP algorithm and the GA-BP algorithm, it is demonstrated in detail how the prediction model can effectively predict the remaining service life of the PSD system with high precision, so that the equipment early warning before failure occurs to ensure the normal operation of subway lines. Experimental examples effectively prove the stability and accuracy of the GA-BP algorithm proposed.

Study on the Performance of Adjustable Platform Screen Door in Subway Stations

In the last decades, the construction of subway systems has been in rapid progress in metropolis. Former studies have pointed out that substantial amount of energy is consumed by subway stations. Thus, the adjustable platform screen door (APSD) system is widely adopted, which is characterized by the energy-saving in both the cooling season and the transitional season. However, the installation of APSD system might result in thermal discomfort for passengers, which lacks investigation. This study aims to study the performance on the thermal comfort of subway station with APSD system. In this process, Computational Fluid Dynamics (CFD) Simulation was conducted using PHOENICS to obtain the velocity and temperature distribution under 3 kinds of train arrival patterns. Furthermore, Relative Warmth Index (RWI) was used to assess thermal comfort. The results show that the velocities of the platform and station hall are below 2.5m/s and 3.7m/s respectively, which is closely related to the train arrival pattern. With regard to the platform occupied zone, the RWI is between 0.04 to 0.19, which is almost within the thermal comfort zone according to the ASHRAE comfort classification. Nevertheless, for the occupied zone of the hall, the RWI is between 0.15 to 0.52, indicating relatively warm.

Energy consumption of subway stations in China: Data and influencing factors

Subway transportation systems are in rapid development and energy consumption in subway stations is becoming more and more significant. The present paper aims to reveal the electricity consumption of subway stations for non-traction purpose, and data from 341 subway stations in 5 cities in different climate zones in China have been statistically integrated and analyzed. The results demonstrate that the average annual electricity consumption ranges 1.8–2.3 million kWh in underground non-transfer stations. Electricity consumption per unit floor area is taken as the benchmark to evaluate the energy performance with an annual average value of 131–144 kWh/m2 in each city. The VAC (ventilation and air conditioning) system and lighting system are found in dominant positions of the total electricity consumption, accounting for about 46% and 27% respectively in City A. Influencing factors of the energy consumption are also analyzed, including floor area, annual passengers, CDD (cooling degree days), service year, PSD (platform screen door) system, platform type and number of entrances. These factors are compared and classified into three categories according to the degree of influence on energy consumption. The current information provides references for understanding the energy consumption level and establishing energy consumption standards for subway stations.

Energy performance investigation of an innovative environmental control system in subway station

More than 70% of the non-traction energy consumption is attributable to environmental control system in subway stations, in which ventilation system accounts for the largest portion. Energy savings will be affected significantly if the environmental control system can be improved effectively. This paper proposed an innovative environment control system. The system features an innovative platform door with controllable vents, aiming to improve the energy performance and thermal environment in subway station. This study used on-site experimental data and numerical simulations to analyze the thermal environment of the station for optimizing the controllable vents of innovative platform doors including position, size and open angle. Moreover, the operation control strategy for the innovative environmental control system was put forward. The energy performance of the innovative environmental control system was discussed for the five cities, which represent five climate zones of China. The results showed the innovative environmental control system could satisfy the requirements of thermal comfort. Compared with the traditional platform screen doors system, the energy consumption could be reduced by 20.64%–60.43%.

Risk Graph에 의해 할당된 SIL에 따른 철도 승강장 도어 시스템의 정량적 Risk 저감 모델

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. Especially, in case of the SIL allocation method without determining of quantitative tolerable risk, the additional review is needed to check whether it is suitable or not is required. In this study, the quantitative risk reduction model based on the safety integrity allocation results of railway platform screen door system using Risk Graph method has been examined in order to review the suitability of quantitative risk reduction according to allocated safety integrity level.

스크린도어(PSD)의 개폐율에 따른 피난소요시간 분석에 관한 연구

Platform Screen Door System (PSD)는 지하철 승객의 편의 및 안전을 위해 설치되기 시작하였고, 현재 전국 9개 운영기관이 관리하고 있는 824개 역사 중 전체의 71.8%에 해당하는 592개 역이 PSD를 운영 중에 있다. 본 연구에서는 전동차 정차 위치에 따른 PSD와 전동차 가동문 사이의 개폐율 변화를 분석하였고, 수도권 지하철을 운행 중인 기관에서 제공받은 재차인원 자료 분석 및 피난시뮬레이션을 통해 각 역사별 피난소요시간을 산정하였다. 연구결과 승객이 매우 혼잡하게 밀집되는 일부 고밀도 역사에서는 PSD 개폐율에 따라 매우 위험한 상황이 초래될 수 있음을 알 수 있었다. 특히 정위치에서 7 m 벗어난 곳에 정차할 경우 PSD의 고정 안전보호벽과 맞물려 열차 출입문 절반 이상이 폐쇄되는 것으로 분석되었다. 이러한 문제점을 개선하기 위해 기(旣) 설치된 PSD 고정안전보호벽을 모두 개폐 가능한 비상문으로 교체 및 개량하는 것을 제안한다. The PSD (Platform Screen Door System) has been installed to enhance the passengers' safety. A total of 592 stations operate the PSD system, which is almost 71.8% of all stations in South Korea. This study compared the opening rate between the PSD and train door, and calculated the exact amount of passengers at peak time. In addition, the evacuation time was simulated by Pathfinder 2015 with the exact input data. Some of the high density stations have extremely high dangerous points about the passengers' evacuation at some situations by the PSD door opening rate. In particular, due to the interference of a fixed door, when it stops at 7 m less than the regular position, its opening rate becomes less than half of the normal state. To solve this problem, it should be made possible to open the fixed door by changing it to an emergency door or improving the PSD module system.

반 정량적 리스크 저감 요소를 고려한 철도 승강장 스크린 도어시스템의 안전 무결성 수준 할당

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

Comparative Study of Rail Transit's Platform Screen Door System Simulation and Test Based on the Finite Element Method

In order to test the reliability of the rail transit's platform screen door system structure, this paper focuses on studying the rail transit's platform screen door system. Through modular design of the rail transit's platform screen door system mechanical structure, analysis and comparative study of the mechanical structure based on the finite element method. Finally, the finite element simulation is verified by the experiment, The test results show that the finite analysis method is reliable. This paper attempts to provide theoretical references for optimization of the rail transit's platform screen door system structure.

결과 심각도 및 리스크 그래프에 기반한 철도 승강장 도어시스템의 안전 무결성 수준 할당

Abstract : There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or asse ssment is not easy since absence on clear criteria or common definition . This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of met hodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

An innovative environmental control system of subway

An innovative platform screen doors (PSDs) system with controllable slits was introduced, aiming to improve traditional PSDs and automatic platform gates (APGs) system. A newly-built subway station was used as a prototype to analyze and demonstrate the feasibility and energy savings opportunities of this innovative system. The process of train arrival and departure at a station was studied by transient simulation using computational fluid dynamics (CFDs) method, and the calculation of CFD was validated. Comfort, air ventilation and energy savings achievements in the station from piston wind were analyzed. After analyzing the thermal environment of the station and tunnel and five operation models, a new control scheme was implemented in this paper. Energy savings from the new control scheme used in eight cities were calculated. The results show that the new environmental control system meets comfort requirements. When compared with the traditional PSDs system, energy consumption is reduced by using optimized opening and operating programs. The energy savings of the new control scheme in different cities are remarkable, especially during the “shoulder” months when air conditioning is not available in the system.

A100 Key factors influencing air quality in rail subway systems

Abstract Background Air quality plans incentivise the use of public transport to abate atmospheric emissions from private road vehicles in cities. In this context rail subway systems are especially desirable as they are based on electric trains, are energetically/environmentally efficient, and help relieve surface traffic congestion. However, a number of studies have revealed poor air quality underground, especially concerning levels of Particulate Matter. Interestingly, some subway systems appear to be worse than others in terms of particle loading, and it is clearly necessary to identify the key factors involved. Methods Ambient subway aerosol particles present in trains and on platforms in the Barcelona metro system have been (and are being) intensively monitored, sampled and physico-chemically characterised, and different types of stations compared. Air monitoring equipment includes high volume samplers for chemical analysis of particles below 2.5 μm, a light-scattering laser photometer for particle concentrations in 3 sizes, and an indoor air quality meter for carbon oxides. Results Outdoor concentrations of traffic particles and gases in Barcelona city do not significantly influence subway air quality, with most particles being ferruginous and sourced underground. Air quality is better inside trains than on platforms, although passenger density clearly affects carbon dioxide levels in both. Stations with cleanest particle concentrations are those fitted with new platform screen door systems, whereas the poorest air quality is associated with older-style narrow single track-tunnel-platform designs. Particle concentration varies along the platform, being influenced by the number and position of passenger exit tunnels, the train frequency and travel direction. Particle composition and morphologies are similar in all stations, indicating a common mechanism of formation, and they are physically and chemically distinctive from particles breathed in outdoor urban air. The iron-rich particles are mostly nanometric in size and derive from mechanical processes of sliding and wear at the brake-wheel and wheel-rail interface, with minor contributions from high temperature processes such as sparking. Conclusions Air quality in the subway environment is an issue of concern due to the high particle concentrations that can be registered, especially on platforms. The variables influencing these concentrations include type and intensity of ventilation, station design, number and location of accesses to platforms and number of trains and passengers. The detailed study of these parameters in a large number of stations within the ongoing research projects METRO and IMPROVE LIFE is enabling us to develop protocols aimed at producing discernible improvements to rail subway air quality.

Identification of the sources of PM10 in a subway tunnel using positive matrix factorization

The level of particulate matter of less than 10 μm diameter (PM10) at subway platforms can be significantly reduced by installing a platform screen-door system. However, both workers and passengers might be exposed to higher PM10 levels while the cars are within the tunnel because it is a more confined environment. This study determined the PM10 levels in a subway tunnel, and identified the sources of PM10 using elemental analysis and receptor modeling. Forty-four PM10 samples were collected in the tunnel between the Gireum and Mia stations on Line 4 in metropolitan Seoul and analyzed using inductively coupled plasma–atomic emission spectrometry and ion chromatography. The major PM10 sources were identified using positive matrix factorization (PMF). The average PM10 concentration in the tunnels was 200.8 ± 22.0 μg/m3. Elemental analysis indicated that the PM10 consisted of 40.4% inorganic species, 9.1% anions, 4.9% cations, and 45.6% other materials. Iron was the most abundant element, with an average concentration of 72.5 ± 10.4 μg/m3. The PM10 sources characterized by PMF included rail, wheel, and brake wear (59.6%), soil combustion (17.0%), secondary aerosols (10.0%), electric cable wear (8.1%), and soil and road dust (5.4%). Internal sources comprising rail, wheel, brake, and electric cable wear made the greatest contribution to the PM10 (67.7%) in tunnel air.ImplicationsWith installation of a platform screen door, PM10 levels in subway tunnels were higher than those on platforms. Tunnel PM10 levels exceeded 150 μg/m3 of the Korean standard for subway platform. Elemental analysis of PM10 in a tunnel showed that Fe was the most abundant element. Five PM10 sources in tunnel were identified by positive matrix factorization. Railroad-related sources contributed 68% of PM10 in the subway tunnel.

상하개폐형 RPSD의 수동개폐 알고리즘 개발 및 평가

승강장 안전문은 긍정적 평가에도 불구하고 수도권 도시철도에만 100% 설치되어 있으며, 일반철도(Intercity Railroad) 승강장의 경우 승강장 안전문 설치가 전무한 상황이다. 이는 대부분의 도시철도에는 동일 형태의 열차(차량)가 정차하는 것과는 다르게 일반철도에는 KTX, 새마을, 무궁화, 누리로 등 다양한 형태의 열차가 정차하고, 자동운전시스템(ATO)이 없이 운영되기 때문에 기존 승강장 안전문 설치에 한계가 있기 때문이다. 현재 연구개발 중인 상하개폐식 승강장 안전문(RPSD)는 열차의 길이 및 출입문 위치, 출입문 개수와 상관없이 모든 열차가 혼용하여 사용할 수 있는 안전시스템으로 일반철도 승강장에 매우 유용하다. 본 논문에서는 잠금장치가 없는 RPSD의 기계적 메커니즘을 고려하여 수동개폐 알고리즘을 개발하고 그 기능 구현에 대해 실험적 방법으로 평가하였다. 그 결과 RPSD의 수동개폐 알고리즘은 전원이 공급되고 있는 조건에서는 매우 효율적인 방법이라는 점을 확인할 수 있었다. Though the Platform Screen Door System (PSD) has received a positive evaluation and is installed in all the Urban Railroad platforms, PSD is not installed in the Intercity Railroad platforms. The limitation of PSD in the Intercity Railroad platforms is due to the fact that first, various types of trains such as KTX, Saemaeul, Mugunghwa, and Nuriro stop at the platforms and their locations of the doors are different and secondly, they are not operated under ATO (automatic train operation). RPSD system currently under research and development, on the other hand, is based on the improved door that slides up and down and can be installed in any Intercity Railroad platform regardless of the length of the train, the location of doors, and the number of doors. This study considers the mechanism of RPSD, develops a manual open/close algorithm, and evaluates the function of RPSD. The results show that the manual open/close algorithm achieves a significant improvement in efficiency when provided with power supply.

Formal verification and simulation for platform screen doors and collision avoidance in subway control systems

For hybrid systems, hybrid automata-based tools are capable of verification, while Matlab Simulink/Stateflow is proficient in simulation. We propose a co-verification procedure, in which the verification tool SpaceEx/PHAVer and simulation tool Matlab are integrated to analyze and verify hybrid systems. For the application of this procedure, a platform screen door system (PSDS, a subsystem of the subway control system), is modeled with hybrid automata and Simulink/Stateflow charts, respectively. The models of PSDS are simulated by Matlab and verified by SpaceEx/PHAVer. The simulation and verification results indicate that the sandwiched situation can be avoided under time interval conditions. We improve the model with four trains and four stations on a subway line and analyze the urgent control scenario for the safety distance requirement. In this paper, the Simulink/Stateflow model is a refinement of the SpaceEx/PHAVer model, which is closer to a final implementation. Moreover, the two models are complementary for some features (e.g.,visualization of simulation, correctness proving by verification), stressing different aspects of the overall system and permitting complementary analysis techniques, i.e., verification versus simulation. We conclude that this integration procedure is competent in verifying subway control systems.