RFID-Based Network for Personnel and Mission- Critical Asset Tracking in a Disaster City

Transcription

1 RFID-Based Network for Personnel and Mission- Critical Asset Tracking in a Disaster City Ben Zoghi 1, Bob McKee 2 1 Texas A&M University, zoghi@tamu.edu 2 Texas Engineering Extension Service, bob.mckee@teexmail.tamu.edu Abstract The purpose of this paper is to describe a successful undergraduate research project and lessons learned. The project scope is to design, implement and test a proof of concept for personnel and mission-critical asset tracking at the Texas A&M Disaster City site utilizing RFID system. On a larger scale solution, this system can be used for underground mine safety and communications, subterranean building safety and communications, indoor/outdoor Personnel tracking, indoor/outdoor Moveable asset tracking, environmental test and measurement, and continuous data logging, trending and homeland security concerns. Our approach is to start with a proof-of-concept scalable system architecture that could be used for a full-scale system. This is an excellent example of how multiple industry partners can impact undergraduate education on a realworld project while seeking new applications for their products and solutions. Index Terms Radio Frequency Identification, Disaster City, Active and Passive Tags. INTRODUCTION designed to deliver the full array of skills and techniques needed by today s emergency response professionals. Located adjacent to the world-renown Brayton Fire Training Field, this mini-city has been designed to simulate various levels of disaster and collapse. Filled with real collapsible structures, this state-of-the-art training center features a wide array of infrastructure. The Office of Urban Search and Rescue is very interested in utilizing these advanced technologies and facilities for personnel and asset tracking for fire fighters, natural disaster events and homeland security. It simulates dozens of scenarios that look towards better emergency response during drastic situations. In this paper we have offered a solution to track the location of personnel on the training site as well as the presence of equipment being used on that site. This solution will combine active and passive RFID as well as wireless via internets, which will provide tracking data to be viewed through a graphical user interface. SYSTEM DESCRIPTION The Block diagram of the system is shown in Figure 1. Radio frequency identification (RFID) is proving to be a cost-effective approach for saving time, improving visibility and reducing labor requirements for a variety of inventory and personal tracking operations. It uses radio signals to exchange data between a tag (also known as a transponder) and a read/write device (commonly called a reader or interrogator). The tag may be active, which means it has a battery to power its own transmission, or passive, which transmits using power received from the reader in the form of electromagnetic waves. Active tags have longer read ranges when compared to the passive ones. RFID systems have attributes that make them more suitable for use in tracking applications when compared to other technologies like bar codes. The most significant of these is that no direct line of site is required between the tag and the reader to exchange data. Another property that is useful is the read range of an RFID system which can be varied depending on the type of tag, frequency and antenna design. Disaster City is a world leader in emergency response training. It is a place unlike any other in the world. The entire 6.2 million dollar, 52-acre training facility has been FIGURE 1 BLOCK DIAGRAM OF THE SYSTEM The system components can be broken down into two distinct categories, hardware and software system. The first group, hardware consists of the passive RFID equipment, active RFID equipment, transceivers and bridge, the S2C-7

2 interface computer and finally all power and hard-line communications equipment. The second group, software consists of the Personnel and Asset database, the RFID reader software and the Graphical user interface software. HARDWARE The first component in the hardware category is the passive RFID reader. This reader s function will be to log the presence of certain types of equipment being used at the training site. This will be done by placing passive, label style, tags on equipment used by Disaster City. When a training unit is scheduled to use that particular site, the containers of equipment are brought up to a staging area near to the site in use. This equipment will then be selected by the training unit when they enter the rubble pile. Each person using a piece of equipment will then need to bring this piece of equipment near the passive reader, at a check in station. This will allow the system to log the presence of that piece of equipment and an operator will then match that equipment with the name of the user in the interface window. Due to the nature of passive RFID the range of this reader will be within one meter. The check in station will more easily facilitate this: I. Passive Reader The Passive reader being used for this implementation is the Symbol XR440 passive RFID reader. This reader is a very robust and versatile. It transmits at MHz and is capable of ranges in excess of one meter. This range is accomplished with the high gain antenna provided by Symbol. This reader s main draw was its ability to transmit its data over internet protocol allowing it to be easily integrated with the transceiver. This is done by a crossover CAT 5 cable from the reader to the transceiver. Specifics of the transceivers will be discussed later in this section. Power for the reader is supplied by a 120 VAC power supply. The reader has a durable casing and is well suited to the temperatures found in the area. Power for the reader will be delivered from an existing outlet located at the base of a light pole where the check in station will be located. A description of the programming and setting used for the passive reader will be described in the software section. II. Active Reader Active RFID readers are used to facilitate the tracking of personnel across a localized area. These readers will be equipped with long range UHF Yagi antennas, which will be used to identify the presence of personnel within Rubble Pile 1. Two active readers will be used to more accurately cover the training area. Each reader will be required to have a range of approximately 50 meters, this is necessary in order to cover the large area of the rubble pile used in the training scenarios. The high gain Yagi antennas will allow for better directionality and therefore more accurate sensing of tags within the specified rubble pile. It is important to not sense tags that are outside of the training sites perimeter. The active reader being used for this system is the Axcess Network Receiver. This reader transmits at 315 MHz and is capable of transmitting the acquired data back to the user over a variety of methods. The method used in this application is serial over RS232 to the transceiver, which will be discussed later. Power for this device is provided by a 120 VAC power supply to be converted to 24 VDC. Since this is intended to be a permanent system the 400 ma draw is negligible. As with all devices in this system it is necessary for the device to be able to operate in a variety of temperatures ranging from -40 to +185 degrees Fahrenheit. The active reader will also be housed inside a NEMA 4 rated enclosed to ensure weather resistance. III. Activator In order for the active tags to operate they need to pass through an activator field provided by another device located at the check in station. This device, the Axcess Activator, enables the active tag and sets it to its beacon rate. For this site this rate has been set to 5 minute intervals, and is programmed into the tag at the factory. There are several different menu settings within the reader that allow some customization for the setting. These internal settings will be discussed in more detail in the software section. The Activator, in order to easily facilitate its function, will be mounted in the same enclosure as the Passive reader, located in the check in station. This will force all personnel to pass through the activator field before entering the ruble pile. The activator uses a switch plate antenna transmitting at 126 khz in order to create a wake up field for the tag. This field can be adjusted via a small screw located in the back of the activator. In order to enable the beacon feature on the tag it is necessary to change several of the jumpers inside the activator. Jumpers J12 and J13 should be placed in the off position in order to enable this feature. IV. Active Tags Each person getting trained at the facility will be issued an active RFID tag when he or she begins training at the facility. This tag will be kept on that person at all times while on the training site. These tags are proprietary with Axcess and operate only with the Activator and Network Receiver. Tags in this type of environment will be exposed to a large amount of shock and light impact, this necessitates the tags to be sealed and packaged accordingly. As mentioned earlier each tag must be set to its intended beacon rate at the factory, for this prototype all tags have been set to a 5 minuet interval, this will prolong tag life. V Transmission equipment The RFID readers will be connected to an g transceiver, which will allow the data coming out of the reader to be transmitted to the bridge. This transmitter takes the serial data, packetizes it, and then transmits out using the standard g. This will allow for connectivity across long ranges outdoors without the need for wired communication. The device used for this operation is the S2C-8

3 Lantronix WiBox 2100E. This device accepts either serial connection over RS232 or with a crossover Ethernet cable. The Passive reader will be connected to the WiBox with the crossover Ethernet cable, while the active readers will be connected via RS232. This unit also requires its own power through a power supply connected to the permanent outlet power available on the site. Device power is 9 to 30 Volts DC, and consumes up to 2 watts of power. Again due to the permanent use of the system its power requirements are negligible. There are several settings that must be adjusted in order to set the system up correctly for a wireless network. A null cable with DB9 connectors must be used for programming the WiBox. These settings will be discussed in depth in the software section. The device that ties the whole system together is the bridge used to collect all of the information from each of the devices and transmit it to the user interface. This prototype will use the Tranzeo TR-CPE90-15 Bridge to facilitate this ability. This device transmits at 2412 to 2462 MHz and is fully capable of receiving and retransmitting Internet Protocol. Power for this device is provided by power over Ethernet. This provides for a much more easily installed device and eliminates the need for an extra power wire to be run to the device. The bridge is built to be installed outside and is weather resistant and operates in temperature ranges from -40 to +60 degrees Celsius. An important note with this device is to make certain that it is properly grounded; improper grounding could result in damage to the bridge. VI. Cables and Connectors Once all components are assembled together it is necessary to run power to each of the readers. This is accomplished through an outlet strip in each enclosure and long extension cords to generators located on site. As discussed earlier power for the bridge is provided over the CAT5 Ethernet cable and will not require a separate power cable. Other cables needed for this system are a crossover Ethernet cable, two RS232 cables, a 100 foot straight through Ethernet cable and a null cable with DB9 connectors. The null cable is used only for programming of the WiBox. Coaxial cable with BNC connectors are used to connect the readers to the antenna for each of the devices. The length of these cables should be less than 25 feet each to ensure an accurate signal. The interface will be loaded onto a computer provided by Disaster City and needs only be capable of internet access to the network created, as well as several pieces of software which will be discussed in the next section. SOFTWARE There are several types of software that needed to be created in order to facilitate integration of the overall system. The first type of software is the internal programming to each of the individual components mentioned before. This allows the user to change the settings in order for the device to operate. This is required for the Passive and Active readers, the bridge and the transceivers. The second type of software is created in order to facilitate integration of the system, as well as the graphical user interface. I. Settings These devices required some settings to be changed for operation according to the needs of Disaster City. These settings are changed through HyperTerminal and an RS232 cable. The communication settings for HyperTerminal are as follows. Bits per second (Baud) : Data Bits: 8 Parity: None Stop Bits: 1 Flow Control: None Each Receiver looks at the Activator ID transmitted by the tag in order to classify the tag data. The Activator ID used by the system will have to be added to the allowed list of ID s. This is done by simply entering 254+ into the window. Then enter 33c to confirm that the change has been made. This sets the allowed activator ID to 254, this is the ID used for advanced tag modes that are being used in this system. Once this is done the serial outputs will be active with the allowed Activator ID. The Axcess Activator also required some changes in order to enable the beacon rate within the tags as they pass through the activation field. In addition to the hardware changes discussed in an earlier section there are a few settings that must be changed as well. Using HyperTerminal and a RS232 cable connected to the Activator enter the command 37c into the window, this will clear all activator ID s from the system. Then type command 254+, this will allow the activator to set ID of 254 for advanced tag mode. Once this is done place a tag in the activation field to verify its operation. It is important when setting up the system that the Network Receiver is configured to allow for the Activator ID number mentioned. Failure to do this will result in an inability to receive the incoming tag ID. The next piece of equipment that needs setting changes is the WiBox transceiver. There are two different configurations for this device: the connection to the Passive reader, and the for connection to the Active readers. The WiBox settings for the Passive reader can be seen in Table 1. All settings not listed in this table are to be default settings. The Active reader also requires a WiBox with its own internal settings. These settings are the same for both of the active readers and will allow them to transmit all of their data over wireless internet. All the settings for the WiBox while in use with the active readers will be the same as that of the one used with the Passive reader except for the Server Option. With the active readers the Server Option should be selected to Wireless only. S2C-9

4 Setting Server option Topology Network Name Security Authentication Encryption Key TX Key Index TX Data Rate TX Data Rate Power Management TABLE I WIBOX SETTINGS FOR PASSIVE READER Selection 2=Bridging 0=Infrastructure Wireless 1=WEP 0=open/none 2=WEP128 1AA CC295AC7A6BD45 1 1=Auto Fallback 3=11MBPS N The Passive reader has several settings that must be changed in order for the system to operate as designed. In addition to these settings there is internal programming that must be added to the reader in order to facilitate its operation. At this time the internal programming is non operational, causing part of the system to also be nonfunctioning. However, the settings will be discussed here so that the system may become operational at a later date. The passive reader settings are adjusted through two different modes of operation. The first is through the serial interface, using an RS232 cable and the HyperTerminal program. In HyperTerminal use the following communication settings. Transfer rate: bps Data bits: 8 Parity: NO Stop bits: 1 Flow control: NO Hardware compression: NO The settings to be changed will differ for each system dependent upon the network configuration desired. The settings are as follows: II. Graphical User Interface (GUI) The Graphical User Interface allows the user to see the presence of all personnel, and assets located at the training site where the system is installed. This interface is designed using Google maps satellite view as a base representation of the training site. The rest of the code was written in PHP, so that the program will be accessible as a web enabled interface. The Interface is linked to the MYSQL database so that the information on each tag can be associated with the assets in Disaster City. The code for the interface is primarily aimed at taking in the data that each piece of equipment in the field transmits back to the host computer. The program reads the raw data that comes in and parses it for the particular data that the system is looking for. In this case it is looking for tag ID s and Activator ID s transmitted by the active readers. It accepts the incoming Ethernet packet from the bridge, and verifies that it is a valid packet of data, in other words that the packet matches certain criteria that verify it has not been corrupted or transmitted incorrectly. Once this is verified the program verifies four pieces of information transmitted, the Network Receiver ID, the Activator ID, the Facility code and finally the Tag ID. Each piece of data is then stored for use in the PHP programs that enable the interface. This process is completed each time an Ethernet packet is received by the system. This program continues to run until terminated by the user in the command console. The Passive reader software will operate in the exact same way as the active reader software. The primary difference will be in the method that the program parses out the data from the Ethernet packets. The main component to the interface is the PHP code that allows the user to see the visual representation of the data that is collected. DHCP off IP Address: TCP Port: 3000 Mask: Gateway: DNS Host: HTTP Server: ON HTTP Port: 80 Telnet Server: Enable FTP Server: Enable Watchdog: Enable Trusted Host only: Off Once the network is established, the reader is then accessed through the Administrator Console. This is accessed by typing in the assigned IP address for the reader into a web browser. This will allow the user to read tags and see the data in real time. FIGURE 2 USER INTERFACE FRONT PAGE. The user interface is the backbone of the system; as such it was necessary to design it so that it was relatively simple to use. The front page of the designed user interface can be found in Figure 2. The window in the middle of the map page shows each of the tags that are tracked within Ruble Pile. The interface has three main components to it. The first is the map of the training area. On this map the S2C-10

5 locations of the different training areas will be shown. The second section on the right of the interface shows the missing personnel from the site. This section will show when a person has not been seen by the system in over ten minuets, allowing the trainers to quickly identify a potential problem. The third section of the interface on the left is the inventory and personnel update links. These links allow the user to perform a variety of tasks pertaining to the trainees and the assets of Disaster City. While there are personnel located in the training site their individual ID tags will broadcast their presence at five minute intervals. This will be displayed on the screen along with the date and time. This window is dynamic and will resize itself to fit the number of Active Personnel in the system. By clicking on the active personnel the operator can bring up the name and information on the trainee that ID belongs to. The center section also displays the asset tracking information available. This window is seen in Figure 3. Each piece of equipment that is checked out to a trainee will be displayed in this window. This allows the operator to see exactly what pieces of equipment are being used at any given time. As mentioned earlier the passive RFID reader used in asset logging will be placed near the staging area for training at rubble pile one. This reader will draw its power from an existing electrical connection located at the base of a light pole. Also located at this position is the Axcess Activator. Two active readers are placed on the sides of the rubble pile as shown by the dots on the edge of the rubble pile. All readers then communicate back to the g Bridge located at the position marked with a yellow dot. Power and communications for the bridge will then be run overhead to the office where the user interface will be. The positioning of all of the equipment is intended to give the limit interference in the transmissions as much as possible. Equipment Placement will need to be taken into account should the user want create their own system. FIGURE 3 FRONT PAGE WITH ASSET INFORMATION. By clicking on the asset, the operator can view the checkout log for that piece of equipment. This shows who the asset is checked out to, as well as any other pieces of equipment that trainee might have checked out. When checking out inventory for the first time the operator will have to enter in the personnel that are checking out the equipment. This is done in the Checkout Inventory window. The equipment is selected in the top drop down box while the trainee receiving the equipment is selected from the bottom drop down. This can be changed at any time. The user must press the Enter Results button to commit changes. EQUIPMENT PLACEMENT Due to the layout and construction of Disaster City it will be necessary to construct the system around existing structures and take the layout of the training site into consideration. Figure 4 is a satellite picture of the training site and has been marked with the locations of each piece of equipment. FIGURE 4 EQUIPMENT LOCATION. CONCLUSION A successful proof-of-concept project was delivered to our customer. In addition to the technical side of the project, there were other aspects that we did learn through this project. Here are some of the lessons we did learn: Written communication with sponsor and our faculty sponsor was a must, providing biweekly reports on status of the project and trying to understand the return on investment aspect from our customer, there was no room for partial credit since the customer expected a fully functional working system, and more importantly if the project was not fully ready, one of the student had to delay his graduation by a semester! This project reinforced most of the courses taken in earlier years and fully integrated those into a cohesive powerful project. We focused on technical aspect of the project through this paper but the indirect benefit of being able to work effectively in a team with a real customer on a real project was the best part of our learning experience. S2C-11

6 ACKNOWLEDGMENT The authors would like to thank Disaster City management for giving this opportunity to work in the field and funding this project. Special thanks to private industry, Axcess Inc. in Dallas. A lot of hard work went into this project by two undergraduate students, Mike Waters and Andrew Arnolds in the Electronics Engineering Technology at Texas A&M University. Mike joined HP as a software engineer in Houston and Andrew joined TAC control company as a hardware engineer in Dallas. REFERENCES [2] Disaster City, plateid=1117 [3] Google maps API, AUTHOR INFORMATION Ben Zoghi, Professor, Engineering Technology and industrial Distribution, Texas A&M University, College station, zoghi@tamu.edu Bob McKee, Director, Disaster City, Division Director for the US&R Division, Texas Engineering Extension Service (TEEX), Sponsoring Agency Chief TX-TF1, bob.mckee@teexmail.tamu.edu [1] The History of RFID Technology," RFID Journal, S2C-12