Improved ergonomic layout design of subway control center based on virtual simulation technology and genetic algorithm

An initial ergonomic layout analysis framework based on physical constraints

A subway control center is a multi-level command center. The rationality of space design for dispatcher operation activities is mainly reflected in the rationality of console size design.¹⁶. In accordance with the requirements of human factors engineering, human capabilities, physiological limitations, and psychological needs must be considered when designing a console. The console's design data must match the characteristics of the user's group.

Console design should be based on work analysis. Each task and its results, as well as the requirements of the corresponding work area, form the basis of the console design.¹⁸. In addition, the shape of the console is influenced by the characteristics of the input device, the use of communication and display devices, the frequency of use, and interaction with other positions.¹⁹. The console's human-adaptive design should follow these steps: First, analyze each position's responsibilities and requirements for the display and control equipment it will use, including number of users, visual requirements, and communication with other positions. Then, list the display control equipment (displays, operation dispatchers), communication equipment, and other work equipment that must be used in each department, and provide detailed explanations of screen sizes, displays, control equipment, etc. . We design the layout, structure size, and maintenance work space of the console display control device according to the work content and working posture. Finally, the geometric size of the entire console is determined.

After preliminary work investigates the space requirements of the dispatcher's console at each post, combined with the personnel requirements of the control center operations management, consoles in various positions can be placed in the control center to obtain the physical layout. . Since there are a large number of personnel at the control center, we consider the optimal placement by comprehensively analyzing the flow of people.

Ergonomic physical space limitations and layout choices

The main constraint is that the Shanghai Metro control center must have a total of 14 lines that compile the ISO11064 series standards, Chinese national standards, and industry standards.^{10, 20, 21, 22, 23, 24, 25}. In the first stage, a total of 14 lines will need to be installed. All 123 dispatch stations and conference tables must then be placed. According to the layout requirements of the subway control center, actual building limitations and user constraints, his four general layout schemes for the Shanghai subway control center were designed, as shown in Figure 2.

Layout option A places the COCC and conference table in the center of the stairs behind the control center. Network video surveillance and network power dispatch are centered on the left and right sides of the step, respectively, and the other locations are OCC traffic dispatch and general dispatch locations. The dispatch desks are arranged in a symmetrically inclined inner arc layout. A 2+6(7) layout is adopted depending on the number of dispatch positions required for the route.

Layout option B concentrates the COCC, regional dispatch officer, and conference table on the stairs behind the control center. Network video surveillance and network power dispatch are centered on the left and right sides of the step, respectively, and the other locations are OCC traffic dispatch and general dispatch locations. The control panels are arranged in a straight line and are arranged horizontally. The control consoles for the OCC area, network video monitoring, and network power dispatch area are arranged in a 5 + 4 manner, except for his two control consoles located in the column area.

Layout option C places the COCC and conference table in a central position in front of the control center. Network Video Monitoring and Network Power Dispatch are located on the left and right sides of the COCC area above the stairs in front of the Control Center. The remaining positions are OCC transportation dispatch positions and general dispatch positions. Dispatch desks are arranged in a straight line, tilted symmetrically, arranged along a line, and arranged in groups of three to four positions.

Layout option D places the COCC and conference table in a central location in the control center, with network video monitoring and network power supply on the left and right sides of the COCC area, respectively, above the stairs in the center of the control center. . Related positions are OCC transportation dispatch, general dispatch, and regional dispatch supervisor positions. Dispatch desks are arranged in a straight line, tilted symmetrically, arranged along a line, and arranged in groups of three to four positions.

Analysis of human resource mobility

The layout design of a subway control center considers the influence of multiple factors, such as the overall structural size of the control hall, the location of exit aisles, the relationship between consoles, and the need for communication between staff, visitors, and management. need to do it.Process changes Emergency post availability, arrival, evacuation, number of personnel and its dynamic changes¹⁷.

This study used the discrete simulation-based pedestrian microsimulation software LEGION to evaluate the overall initial layout of the control center. It is a method of discretely simulating human behavior in the process of building and analyzing a simulation model, and one individual in a crowd is considered as the research object. More attention was paid to individual behavioral characteristics and the relationships between them. The simulation required to account for various parameters and behavioral characteristics of individuals in a crowd truly reflects the interactions between people and between people and surrounding obstacles.²⁶. Furthermore, to simulate the behavioral characteristics of individuals during evacuation and movement in the subway control center, it was necessary to simulate passenger flow situations during normal and emergency conditions. Therefore, the simulation analysis of the entire control center layout is divided into two aspects. First, the control center dispatcher must enter a designated position in the control center at the same time as the shift transition. To effectively improve the efficiency of control center shifts, find out when staffing is available. Short layout plans that are not densely populated require simulation analysis of personnel arrival. Next, an analysis of how to safely evacuate personnel within the control center is considered in the event of a crisis situation. Legion has impressed with his three Olympics since 2000 and London's Olympic bid project²⁷. Furthermore, it has been applied to rail transportation, such as New York subway planning and Hong Kong subway station planning.²⁸. Therefore, in this paper, we performed a simulation using Legion.

A method based on discrete simulation experiments is adopted to improve the efficiency of safe evacuation, reduce shift work time as an overall layout plan selection idea, and compare and screen different layout plans. The evacuation and migration simulation analysis steps of the Shanghai subway control center are as follows:

• Step 1. Build an overall layout scheme model for your control center.

  According to the four general layout schemes of the control center designed above, a 2D planar layout CAD drawing is drawn to establish the simulation scene for the next step.

• Step 2. Determine the dispatcher attribute parameters in the control center and run the simulation model.

  First, set the simulation execution time. Next, enter the attribute parameters of the dispatcher, such as the cargo transportation status, and the speed parameters calculated from the gender and age ratio of the dispatcher. Next, determine the walking route for the person in charge. Finally, establish the analysis line and run the simulation. Basic information on Shanghai subway dispatch staff will be collected through a questionnaire survey. These are analyzed and processed as input for the workforce attribute parameters. The data are shown in Tables 1 and 2.

  By referring to the relationship between walking speed, gender, and age of personnel obtained from experiments conducted by the International Maritime Organization (IMO) and combining it with the above survey data, the speed data of command personnel with different gender and age distributions are shown in Table 3. obtained as shown.

• Step 3. Simulation analysis of the overall layout scheme of the control center.

  Analysis metrics for simulation output include evacuation time, headcount statistics, cumulative high density maps, cumulative maximum density maps, etc. To reduce random errors, each subway control center layout option is simulated independently 15 times to eliminate instances of problems. Evacuees have not been completely evacuated. The 3δ criterion is used to exclude simulation data where the absolute value of the difference from the mean value of the simulation time is more than three standard deviations. The average pumping time for the four layout methods is shown in Figure 3. It can be seen that among the four layout methods, the average evacuation time of method A is the shortest, and the evacuation time of method B is close to the average evacuation time of method A. .

  

  Evacuation time for four layout schemes.

SPSS24.0 software was used for data statistics and analysis. The significance level from the Levene homogeneity of variance test was 0.221. The overall distribution of evacuation time for different layout schemes can be considered to be uniform. Therefore, a one-way analysis of variance was performed. The results are shown in Table 4.

p < 0.05 indicates that the layout option has a significant effect on evacuation time. From the perspective of improving evacuation efficiency and shortening evacuation time in an emergency, the control center layout plan is selected first, layout plan A with the shortest evacuation time is selected first, and then overall layout plan B is selected. It was decided to.

When performing detailed analysis, the cumulative maximum density map displays the maximum population density level for a given area from the start of the simulation to the end of the simulation. This is used to measure the ability of a simulation analysis area to withstand certain criteria. . In this study, the cumulative maximum density maps of the evacuation simulations of the four layout schemes were used to analyze the withstand pressure levels of different layout options, as illustrated in Figure 4.

Example of cumulative maximum density map for layout options A and B in evacuation simulation.

Evacuation Simulation Analysis Similar to the data processing step, the simulation analysis is performed upon arrival of the control center personnel. The average arrival times for the four layout schemes are shown in Figure 5. It can be seen that among the four layout schemes, scheme A has the shortest average arrival time, followed by scheme C.

Arrival times for four different layout schemes.

A one-way ANOVA was performed on the simulations of personnel arrival times in the four deployment schemes, and the results are shown in Table 5.

p < 0.05 indicates that different schemes have a significant effect on the simulation time after the arrival of personnel. The results confirm that option A is the most preferred of her four options.