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DYNAMIC AND INTELLIGENT EVACUATION SYSTEM FOR TUNNELS Juha Huovilainen Marimils Oy, Vantaa Finland ABSTRACT A dynamic evacuation lighting system, which offers real-time, intelligent control and guiding indication using the specifically designed software has been developed to improve safety in difficult evacuation environments like tunnels. Due to the unique software and guiding light effects, the system will automatically control and guide people towards the safest escape route and away from danger, when integrated with other safety systems such as fire detection, chemical or biological detection systems. Dynamic and intelligent evacuation systems are a more reliable, faster and safer way to control, guide and evacuate people in extreme situations than conventional evacuation systems based on static illuminated exit signs or audio signals. Keywords: Dynamic evacuation, safety in tunnels, emergency lighting 1.

INTRODUCTION

The demand for safety and emergency systems has risen steadily during the last couple of years because of recent tragedies in tunnels. These accidents have created an urgent need for intelligent safety systems to provide critical rescue information and emergency lighting. Current passive emergency systems, cannot adapt to changes in real-time conditions and do not provide enough control, guidance, or information to people in danger. Modern evacuation models, theories and simulators provide the designers and engineers with tools for improving evacuation plans, making them more robust and appropriate given the different emergency scenarios faced. However, until now the practical tools to actually implement these scenarios have been severely limited. The traditional exit signs and photo luminescent stripes can only point to fixed exits which, depending on the situation, may not be the safest ones. In the worst case scenario, for a threat located within the planned evacuation path, some static signage might guide people in the totally wrong direction. A modern tunnel today is equipped with several different sensor and advanced camera control systems but the information from all these systems is mainly used for manual control and human guidance during an emergency situation. An intelligent system is integrated to the tunnel management and information systems and can utilize this information for real time guidance and adapt to real time changes based on the received information from these third-party systems. 2.

SYSTEM OVERVIEW

The main components of the system are the illuminating guiding stripes and controllable guidance signs which, together with the control software, can guide people effectively in extreme emergency conditions in any direction or location. The stripe can display static, flashing and moving patterns of light that come in different colors and intensities. As the human visual perception is highly sensitive to motion, the moving light patterns efficiently notify and guide people towards the right direction (Nilsson, D., Frantzich, H. and Saunders 2005). This is an important factor to overcome typical human behavior patterns under emergency situations (pre-movement behavior and travel behavior) and therefore by

5th International Conference ‘Tunnel Safety and Ventilation’ 2010, Graz

- 193 improving the emergency detection, shortening people’s reaction time and increasing the movement speed we can shorten the evacuation time. The running guiding-light effect in the LED-stripes is generated by bright, long-lasting microLEDs that offer speed variations and active guiding indication, or a continuous highly visible illuminating effect (see Figure 1.). A special stripe design with longer LED-sections has been developed for tunnels where the stripe is usually seen in lower watching angles and from longer distances.

Figure 1: Guiding stripe with green LED-lights The stripes can be mounted at a low level on the tunnel wall or in a handrail (see Figure 2.).

Figures 2:

Different installation methods in tunnels. A LED-stripe and symbol panel installed into an aluminum profile on the tunnel wall and into a handrail in a metro tunnel

The LED-stripes can also be used to improve the visibility of exit doors by mounting stripes directly in the exit door frame or on the wall in the exit door area by using a tailor-made profile which shows the stripe in a 30 ° angle down the tunnel edge ensuring better visibility when people are approaching the exit door along the tunnel. The stripe can also be installed in the road surface in a special profile or inside the road in a vertical position (see Figure 3.)

Figure 3: Different exit door awareness lighting applications. Dynamic green LED-stripes installed on the wall, in the road and in the exit door frame

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SYSTEM COMPONENTS AND ARCHITECTURE

The system components are: •

The LED-stripe is a durable, extremely thin, continuous flexible circuit board with surface-mounted Light Emitting Diodes (LEDs), which is extruded by a specific coating material. The stripe is IP68-rated and made of flame-retardant, non-toxic materials.

•

The symbol and light panels are thin, robust and bright controlling and guiding panels. The panels are based on a globally patented Diffractive Optic (DO) design, and there are many different standardized symbols available. The symbol and light panels are also IP68-rated meeting same requirements than the LED-stripe.

•

The stripe and panel driver allocates unique addresses through the group driver, to each LED-stripe and panel thus enabling the monitoring and controlling of each individual stripe and panel. The data transfer between components takes place through the proprietary protocol.

•

The integrated group driver controls and monitors the state of the stripe, panels and power supply units, and signals an alarm to the system control unit (the controlling tool software) if the preset limits are exceeded.

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The power supply unit is connected to the main supply AC voltage, in order to provide low voltage DC for the subsystem. In the event of a mains power failure, an on-board, sealed lead-acid battery supplies power to the system, for at least one hour.

•

The system control unit is an industrial PC running the controlling tool and monitoring tool software. The system control unit is used by the authorised administrator of the system for controlling the operation of the system, when people must be directed to correct emergency exit routes. The system control unit is connected to the group drivers by the proprietary protocol.

The architecture of a basic system is illustrated in Figure 4. The system is controlled and monitored by the System Control Unit (SCU), which is an industrial PC running the control and monitoring software. The SCU is connected to external systems like fire alarm systems that provide input to the evacuation system. Based on this input the control software chooses the right guidance scenario from a predefined list.

Figure 4: System architecture The SCU controls the stripe and panel drivers over an RS-485 bus that can contain tens of drivers and span up to one kilometer in length. Depending on the model, each driver can control 1-4 LED stripes or up to 12 chains of symbol or light panels.

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SOFTWARE AND SYSTEM FUNCTION

The system adjusts and controls, according to the situation, and guides people to safety, and it helps to provide a logical pre-designed plan of action for any human evacuation situation. The operation of the system is designed and programmed step-by-step with the design and programming tool, starting from the programming of the subsystems, which are the basic structural “building blocks” of the system. 4.1.

The Controlling Tool

4.1.1. Intelligent and Automatic Control The system is normally used as an intelligent system, in which the system receives information from an external control system (for example a fire alarm system), and based on that information directs people to safe exits and away from potentially life-threatening situations. The evacuation is based on predesigned evacuation to avoid human errors in evacuation. The scenarios for different emergency situations are designed based on evacuation and safety know-how from authorities and tunnel safety personnel as well as information of available evacuation routes and exit doors. This is essential information to avoid unnecessary queuing and to use all the existing evacuation capacity in an optimum way. Traditional emergency guidance systems have tended to focus on fire alone. However, modern emergency planning should also take other kinds of hazards into consideration such as chemical leakage, blackouts, terrorist threats, flooding etc... . Depending on the situation, different kinds of threats might require different kinds of actions. 4.1.2. Manual Control The entire system can also be controlled manually by the controlling tool software which runs in the system control unit. With the system control unit’s controlling tool software the responsible operator selects the main emergency exit routes manually, by activating one of the master guidance templates programmed by the system designer in the design and simulation tool. 4.1.3. Automatic or Manual Control with a Control Box The system can also be controlled by a control box for a limited number of evacuation scenarios. Operation is automatic or manual by activating one of the predesigned evacuation scenarios. 4.2.

The Monitoring Tool

The entire system and each addressed component of the system are monitored by the monitoring tool software. The monitoring tool software can be run on-site, through the Local Access Network of the site or remotely through the Internet. The monitoring tool can be installed and run either on a laptop PC or a desktop PC, as long as the system hardware requirements are met. Each group driver and stripe and panel driver is programmed with an address and component serial number, which makes it possible to plan and program detailed emergency exit routes, and to find defective components with extreme precision and accuracy. The monitoring tool can be programmed to send a check question to each system component frequently (with an interval of only few seconds). The answer from every component gives information of the component status and guarantees that every single component of the system is ready and functioning if needed. If one component fails and doesn’t confirm its status by sending back the answer message, a report will be generated for system responsible personnel for corrective actions. This means in practice that no traditional maintenance or manual system check-up is needed to check the system and component status.

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REDUNDANCY

The system can also be equipped with a secondary (slave) system and redundancy to ensure the correct functionality in the event that the system malfunctions or is broken. Scenarios to ensure the system operation in following error situations can be created; • Control signal (= data line) is cut • Master Group Driver malfunctions • Master Stripe/Panel Driver malfunctions • The main supply voltage of the Power Supply Unit with battery backup is cut • Master Power Supply Unit malfunctions • Stripe short-circuits • Stripe is cut System redundancy can be built to several levels (see Figure 5.) for example between two technical rooms, between cabinets and even in the stripe chain between two drivers by connecting stripes at both ends to specific integrated drivers which are dedicated to handle power and data supply to both directions in the chain if one of the stripes in the chain is broken or cut.

Figure 5: System redundancy 6. (1)

REFERENCES Nilsson, D., Frantzich, H., and Saunders, W., Coloured Flashing Lights to Mark Emergency Exits - Experiences from Evacuation Experiments, Proceedings of the Eighth International Symposium on Fire Safety Science, pp. 569-579 (2005)

5th International Conference ‘Tunnel Safety and Ventilation’ 2010, Graz