buildng traffc smulator(bts)

Hierarchy of time phase of total evacuation time in an emergency situationHierarchy of time phase of total evacuation time in an emergency situation

The pre-movement time is about three times longer than The pre-movement time is about three times longer than the actual movement timethe actual movement time

Critical time (Critical time (TcritTcrit) – ) – It is defined as a time limit when the It is defined as a time limit when the evacuation of people is safe and probably no injuries or evacuation of people is safe and probably no injuries or deaths will occur.deaths will occur.

Tp + Tr + Te Tp + Tr + Te ≤ ≤ TcritTcrit

Building Traffic SimulatorBuilding Traffic Simulator (BTS) is a software system (BTS) is a software system for simulating passenger traffic in an arbitrary for simulating passenger traffic in an arbitrary building. building.

Purposes:-Purposes:- To analyze the performance of an elevator system.To analyze the performance of an elevator system. To demonstrate elevator systems for customers.To demonstrate elevator systems for customers. To test elevator group control software.To test elevator group control software.

BTS’s main design choices are affected byBTS’s main design choices are affected by The requirement to be portable .The requirement to be portable . Able to run in everyday PCs.Able to run in everyday PCs.

COM and Active X technologies were chosen COM and Active X technologies were chosen to make BTS run in well known platform i.e. to make BTS run in well known platform i.e. Windows.Windows. Portability can be achieved by separating the Portability can be achieved by separating the code in portable and non-portable component.code in portable and non-portable component.

PortabilityPortability

PortablePortable C++ codeC++ code Can be easily ported Can be easily ported to any platformto any platform It is mainly for non-It is mainly for non-window version PC’swindow version PC’s C++ library C++ library

Non-portableNon-portable visual C++ code, visual C++ code, visual basicvisual basic It contain main It contain main program, displays, user program, displays, user interface, database interface, database interface component interface component Windows specific Windows specific libraries libraries

Figure 2:- Main BTS components and their interaction during the simulation

Figure 3:- Example of process-oriented and event oriented codeFigure 3:- Example of process-oriented and event oriented code

The BTS interface has a building design view for The BTS interface has a building design view for

constructing a specified building.constructing a specified building. The user can draw the floor shape of the building The user can draw the floor shape of the building

for each floor.for each floor.OrOr

The user can draw the floors where the building The user can draw the floors where the building shape is changed.shape is changed.

The elevator and escalator groups can be dropped The elevator and escalator groups can be dropped in their correct positions on the floor.in their correct positions on the floor.

The actual parameters for the building, elevators, The actual parameters for the building, elevators, escalators and passenger traffic are defined .escalators and passenger traffic are defined .

Figure 5:- Design view of the BTS simulatorFigure 5:- Design view of the BTS simulator

Figure 4:- Parameter to be defined before simulationFigure 4:- Parameter to be defined before simulation

A 24-hour traffic period in a building can be A 24-hour traffic period in a building can be simulated.simulated.

Instead of a 24-hour simulation, several Instead of a 24-hour simulation, several simulations can be run in series with different simulations can be run in series with different traffic intensities for some traffic pattern.traffic intensities for some traffic pattern.

This helps in identify This helps in identify the traffic intensity where the traffic intensity where the handling capacity of the elevator group is the handling capacity of the elevator group is reached with the specified traffic pattern. reached with the specified traffic pattern.

Figure 5 :- Lobby view with typical passenger groupsFigure 5 :- Lobby view with typical passenger groups

• A good animation is more illustrative and A good animation is more illustrative and

convincing than statistical figures.convincing than statistical figures.• One can also notice if the elevator system is One can also notice if the elevator system is

clearly insufficient or oversized.clearly insufficient or oversized.

BTS has two animation screensBTS has two animation screens1.Two-dimensional traffic display for one

elevator group.2.Three-dimensional animation that shows the

whole building.

Figure 6 :- BTS building visualizerFigure 6 :- BTS building visualizer

Figure 7:- The main window of BTS showing a 3-D view Figure 7:- The main window of BTS showing a 3-D view [1] and 2-D view of an elevator group.[1] and 2-D view of an elevator group.

It help us in finding these questions:-It help us in finding these questions:-

1.1.How long a passenger has to wait for an elevator.How long a passenger has to wait for an elevator.

2.2.How long the whole passenger journey lasts.How long the whole passenger journey lasts.

3.3.How fast the building is filled or evacuate.How fast the building is filled or evacuate.

4.4.What the assumed energy consumption is.What the assumed energy consumption is.

5.5.How many people in the building can be served by How many people in the building can be served by the defined transportation devicesthe defined transportation devices..

6.6.IsIs the current elevator arrangement is sufficient for the current elevator arrangement is sufficient for the assumed population.the assumed population.

Elevators are planned for peak-up situation.Elevators are planned for peak-up situation.

Residential buildingsResidential buildings

Handling capacity- 5%-7.5% in five minutes. Filling time- 67-100 minutes

Office buildingsOffice buildings

Handling capacity- 13%-18% in five minutes. Filling time- 29-40 minutes

Elevators should be capable of evacuating the population within 15-30 minutes

Elevators can transport 1.5 times more passengers in down - Elevators can transport 1.5 times more passengers in down - peak than in up-peak.peak than in up-peak.

Elevators can transport 1.8 times more passengers in down-Elevators can transport 1.8 times more passengers in down-peak than in up-peak with the help of BTS and modern controls.peak than in up-peak with the help of BTS and modern controls.

Evacuation becomes faster with double-deck or triple-deck Evacuation becomes faster with double-deck or triple-deck elevators.elevators.

In double-deck elevator egress time is reduced to 50-60%In double-deck elevator egress time is reduced to 50-60%of the time with single-deck elevator.of the time with single-deck elevator.

in triple deck the time further reduces to 40%. in triple deck the time further reduces to 40%.

Let us take 3 cases:-Let us take 3 cases:-1.1.All floors are served by all cars.All floors are served by all cars.2.2.The served floors are divided into two zones that are each The served floors are divided into two zones that are each served by half of the elevators. served by half of the elevators. 3.3.Passengers gather at every third floor and elevators serve Passengers gather at every third floor and elevators serve only those floorsonly those floors.

Zoning does not significantly decrease the evacuation time.

The movement of people in stairs can be modeled as unified The movement of people in stairs can be modeled as unified crowd flows.crowd flows. According to flow model egress time is max. of twoAccording to flow model egress time is max. of two

WhereWheret1 t1 egress time (congestion)egress time (congestion)tn tn egress time (free walk)egress time (free walk)n n number of floorsnumber of floorsN N number of people per floor and exitnumber of people per floor and exitFs Fs nominal occupant flow on stairs nominal occupant flow on stairs (persons/m/s)(persons/m/s)W W width of the staircasewidth of the staircasets ts walking time between adjacent floors (free walking time between adjacent floors (free walk)walk)

Assumption for study of evacuation by both waysAssumption for study of evacuation by both ways1.1. Stairs should be placed in the proximity of the Stairs should be placed in the proximity of the elevators.elevators.2.2. Half of the population use elevators and half of them Half of the population use elevators and half of them use stairs. use stairs.

Figure X Figure Y

BTS, an unique tool for studying evacuation and traffic of tall BTS, an unique tool for studying evacuation and traffic of tall buildings.buildings. Provide better and safer transportation.Provide better and safer transportation. Well planned elevators and stairs provide fast ways to evacuate Well planned elevators and stairs provide fast ways to evacuate people.people. Elevator evacuation times were calculated from the up-peak Elevator evacuation times were calculated from the up-peak handling capacity.handling capacity.Handling capacity of a elevator group can be considerably Handling capacity of a elevator group can be considerably increased with double-deck or triple-deck elevators.increased with double-deck or triple-deck elevators. Down peak handling capacity is greater than up-peak handling Down peak handling capacity is greater than up-peak handling capacity.capacity.In tall buildings, shuttle elevators may become a bottle-neck In tall buildings, shuttle elevators may become a bottle-neck during the evacuation and down-peak.during the evacuation and down-peak.

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