Rfid based guidance in remote locations

BACKGROUND OF THE INVENTION

00011. Field of the Invention

0002The invention relates to a real time location system using radio frequency identification (RFID) tags and, more particularly, to one or more RFID tags that communicate with an RFID reader device to alert a user to his/her location within an area and guide the user to a desired destination within the area.

00032. Discussion of Prior Art

0004Global Positioning Systems (GPS) is a space-based navigation system. Within the GPS system, a plurality of satellites transmit signals that can be received at a receiver device (e.g., a dedicated GPS receiver, cell phone, etc.). The GPS receiver unit determines a position utilizing the received signals. It is even possible that the receiver device can then transmit another signal that conveys the determined location of the receiver device. Thus, a user of a receiver device is informed of his/her position and possibly the position information can be shared with another, such as a centralized server, or the like. However, certain areas, in particular, large areas, may inhibit/prevent reception of GPS signals from the satellites. Some example areas that inhibit/prevent reception include areas located underground or within buildings with relatively thick walls. Thus, a method and device for determining a user's location within an area without the use of GPS would be beneficial. Further, it would be useful to have a device that displays the user's current location within the area and guides the user to a desired location, such as an exit. This would be desirable for emergency situations, such as power outages or fires, when visibility is relatively low or non-existent.

BRIEF DESCRIPTION OF THE INVENTION

0005The following text presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

0006In accordance with one aspect, the present invention provides a location system. The system includes a radio frequency identification (RFID) reader device configured to send at least one query signal and receive at least one response signal. The system includes at least one RFID tag positioned within an area. The at least one RFID tag stores unique information associated with a location of the at least one RFID tag within the area. Each of the at least one RFID tag is configured to receive the least one query signal from the RFID reader device and to transmit one of the at least one response signal, conveying the unique information, to the RFID reader device. The RFID reader device is further configured to utilize the at least one response signal to determine a current location of the RFID reader device within the area.

0007In accordance with another aspect, the present invention provides a method of locating a user within an area. A radio frequency identification (RFID) reader device is provided. At least one RFID tag is positioned within the area. The at least one RFID tag is configured to store unique information associated with a location of the at least one RFID tag within the area. At least one signal is sent from the RFID reader device and is received by the at least one RFID tag. The stored unique information of at least one RFID tag is transmitted to the RFID reader device. A current location of the RFID reader device is determined within the area.

BRIEF DESCRIPTION OF THE DRAWINGS

0008The foregoing and other aspects of the invention will become apparent to those skilled in the art to which the invention relates upon reading the following description with reference to the accompanying drawings, in which:

0009<figref idref="DRAWINGS">FIG. 1</figref> is a schematic view of an example area and an example guidance location system in accordance within an aspect of the present invention;

0010<figref idref="DRAWINGS">FIG. 2</figref> is a block diagram of an example RFID reader device and an example RFID tag of the system shown within <figref idref="DRAWINGS">FIG. 1</figref> and in accordance within an aspect of the present invention;

0011<figref idref="DRAWINGS">FIG. 3</figref> is a schematic view of an example display screen of the RFID reader device displaying a path within the area shown with <figref idref="DRAWINGS">FIG. 1</figref>; and

0012<figref idref="DRAWINGS">FIG. 4</figref> is a schematic view of another example display screen of the RFID reader device displaying a path that avoids a dangerous situation.

DETAILED DESCRIPTION OF THE INVENTION

0013Example embodiments that incorporate one or more aspects of the invention are described and illustrated in the drawings. These illustrated examples are not intended to be a limitation on the invention. For example, one or more aspects of the invention can be utilized in other embodiments and even other types of devices. Moreover, certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. Still further, in the drawings, the same reference numerals are employed for designating the same elements.

0014<figref idref="DRAWINGS">FIG. 1</figref> illustrates an example guidance location system <b>10</b> according to an aspect of the invention. The guidance location system <b>10</b> can be positioned within an area <b>12</b>. The guidance location system <b>10</b> can include one or more radio frequency identification (RFID) tags <b>8</b> positioned within the area <b>12</b>. A user can carry (e.g., hold or otherwise secured upon the user) an RFID reader device <b>14</b> within the area <b>12</b>. In general, the RFID tags <b>8</b> can cooperate (e.g., see <figref idref="DRAWINGS">FIG. 2</figref>) with the RFID reader device <b>14</b> via communication of information from the RFID tags <b>8</b> to the RFID reader device <b>14</b> and, thus enable the RFID reader device <b>14</b> to determine a current location of the RFID reader device <b>14</b> within the area <b>12</b>. The RFID reader device <b>14</b> can subsequently display the current location within the area <b>12</b> on a display screen (e.g., see <figref idref="DRAWINGS">FIG. 3</figref>) for the user.

0015The area <b>12</b> (<figref idref="DRAWINGS">FIG. 1</figref>) can include a variety of structures <b>20</b> positioned throughout the area <b>12</b>. For instance, the structures <b>20</b> can include pipes, water tanks, walls, doorways, hallways, exits, etc., such as shown in <figref idref="DRAWINGS">FIG. 1</figref>. It is to be appreciated that the shown area <b>12</b> is only an example and is only generically/schematically shown in <figref idref="DRAWINGS">FIG. 1</figref>. The structures <b>20</b> are not limited in number or location to the shown example, and could be varied in number and/or location within the area <b>12</b>. Also, it is to be appreciated that the type of area could be varied and the types of structures located therein could be varied. Some example area locations include environments such as factories, steel mills, hydro plants, mines, etc. For instance, in one example, the area <b>12</b> could be in a steel mill and the area could include a blast furnace as a structure, or the area could be in a mine and the area could include various mine shaft features, etc. as structures. The area <b>12</b> could further be in an offshore oil platform, wind turbine installation, or the like. In view of the fact that the area <b>12</b> can be varied, it is to be appreciated that the attributes of the area <b>12</b> could be varied. For example, the area <b>12</b> can include locations that have access to a Global Positioning System (GPS) and locations that have limited or no access to GPS. Some specific examples of locations that have limited or no access to GPS can include locations that are underground and/or underwater, such as mines, tunnels, or the like, and locations with thick walls/ceilings, such as power plants, hydro plant dams, etc.

0016Referring still to <figref idref="DRAWINGS">FIG. 1</figref>, the guidance location system <b>10</b> can include the one or more RFID tags <b>8</b> positioned throughout the area <b>12</b>. The RFID tags <b>8</b> can be positioned in a variety of locations within the area <b>12</b>. For instance, the RFID tags <b>8</b> can be positioned on fixed structures <b>20</b> within the area <b>12</b>, including pipes, walls, doorways, hallways, exits, etc. of the shown example. Moreover, the RFID tags <b>8</b> can be positioned in a broad range of locations throughout the area <b>12</b>, such that the RFID tags <b>8</b> cover most or all of the area <b>12</b>. The RFID tags <b>8</b> are not limited to fixed structures, and, as such, can be positioned to mobile structures that can move inside or outside the area <b>12</b>. For instance, the RFID tags <b>8</b> can be positioned on a variety of devices within the area <b>12</b>, such as a mobile asset, including as a forklift, truck, automobile, cart, or the like. The RFID tags <b>8</b> can be positioned such that the RFID reader device <b>14</b> can communicate with one or more of the RFID tags <b>8</b> in most or all locations within the area <b>12</b>.

0017The RFID tags <b>8</b> can be attached to or at least placed proximate to the structures <b>20</b>. In one example methodology, the RFID tags <b>8</b> can be removably affixed to the structures <b>20</b> in a number of ways, including by adhesives, snap fit means, or the like. Accordingly, when the RFID tags <b>8</b> are positioned on the structures <b>20</b>, the RFID tags <b>8</b> and will remain fixed to the structures <b>20</b> unless removed. The RFID tags <b>8</b> can take on a number of sizes, and can be small enough to be positioned out of prominent sight, such as within a light fixture, within a ceiling panel, or the like. Moreover, the RFID tags <b>8</b> can effectively be used in a variety of environments, including high and low temperature environments, environments with high moisture and humidity, etc.

0018Referring now to <figref idref="DRAWINGS">FIG. 2</figref>, a single, example RFID tag <b>8</b> is schematically shown communicating with the RFID reader device <b>14</b> by radio waves to convey information from each respective RFID tag <b>8</b> to the RFID reader device <b>14</b>. It is to be appreciated that although <figref idref="DRAWINGS">FIG. 2</figref> only shows a single, example RFID tag <b>8</b> engaged in communication with the RFID reader device <b>14</b>, similar communication can occur respectively between each of the plurality of RFID tags <b>8</b> (<figref idref="DRAWINGS">FIG. 1</figref>) and the RFID reader device <b>14</b>. Accordingly, it is to be understood that one or more of the RFID tags <b>8</b> can be engaged in the communication. For the communication, the RFID reader device <b>14</b> acts as an interrogator to query the RFID tags <b>8</b>.

0019Turning to possible physical specifics of the RFID tags <b>8</b>, it should be appreciated that such specifics need not be limitations upon the scope of the present invention. Some, example physical specifics can include a variety of different types of RFID tags, including passive RFID tags, active RFID tags, and semi-passive RFID tags. Passive RFID tags do not contain a battery since power is supplied by the communication from the RFID reader device <b>14</b>. Specifically, a passive RFID tag utilizes electromagnetic field properties of the communication from the RFID reader device <b>14</b> for power. Active RFID tags include a battery that can be used as the power source for the RFID tag. Semi-passive RFID tags include a battery but also use power supplied by the RFID reader device <b>14</b> similar to the passive RFID.

0020In the shown example of <figref idref="DRAWINGS">FIG. 2</figref>, the RFID tag <b>8</b> can include an integrated circuit (IC) <b>22</b> that stores and/or processes information. The RFID tag <b>8</b> also includes an antenna <b>24</b> for both receiving and transmitting signals. In one example, the antenna <b>24</b> can transmit stored information from the RFID tag <b>8</b>. The stored information can be unique to each RFID tag <b>8</b> within the area <b>12</b>. Specifically, the unique information can include a variety of information. For instance, the unique information could include the specific location of the RFID tag <b>8</b> within the area <b>12</b>, such as “RFID tag located on the pipe” (e.g., see <figref idref="DRAWINGS">FIG. 1</figref>). In the alternative, the unique information could include only an identification code/number assigned to the RFID tag, such as “RFID tag #<b>135</b>”, or the like. The unique information is utilized by the RFID reader device <b>14</b> as described below.

0021It should be noted again that the RFID tags <b>8</b> in the present example are not limited to the RFID tag shown and described with regard to <figref idref="DRAWINGS">FIG. 2</figref>, and can include a variety of types of RFID tags. For instance, within a passive RFID tag the integrated circuit shown in <figref idref="DRAWINGS">FIG. 2</figref> may simply by a memory, such as EEPROM, which merely delivers information upon the interrogation from the RFID reader device <b>14</b>. Similarly, within an active RFID tag a battery can be included in addition to the integrated circuit <b>22</b> and antenna <b>24</b> shown in <figref idref="DRAWINGS">FIG. 2</figref>.

0022Referring still to <figref idref="DRAWINGS">FIG. 2</figref>, the RFID reader device <b>14</b> can include an antenna which can includes a radio frequency (RF) transmitter <b>26</b> and a RF receiver <b>28</b>. The RF transmitter <b>26</b> can send out one or more signals <b>40</b>, which can be referred to as a query or “ping” signal. Such a signal <b>40</b> can be received by the RFID tag <b>8</b>. The RF receiver <b>28</b> can receive one or more response signals <b>42</b> from the RFID tag <b>8</b>.

0023The signals <b>40</b> and <b>42</b> can have a range limitation (i.e., distance over which a signal has sufficient strength and clarity to be viable). As will be appreciated the signal <b>42</b> can be received by any of the plural RFID tags <b>8</b> (<figref idref="DRAWINGS">FIG. 1</figref>) that are within range and the RF receiver <b>28</b> can receive one or more response signals <b>42</b> from the plurality of the RFID tags <b>8</b> that are within range. As will be described in more detail below, the response signals <b>42</b> can be analyzed by the RFID reader device <b>14</b> to determine a current location of the RFID reader device <b>14</b>.

0024The RF transmitter <b>26</b> and the receiver <b>28</b> can be controlled by a computer system <b>30</b> (<figref idref="DRAWINGS">FIG. 2</figref>), such as a microprocessor, controller, or the like. The computer system <b>30</b> can include any type of system, such as a microprocessor, controller, etc. The computer system <b>30</b> can further operate upon a map <b>32</b> of the area <b>12</b>. The map <b>32</b> may be held in memory or other holding device. The map <b>32</b> can be acquired in a number of ways. For instance, the computer system <b>30</b> can be preloaded to include the map <b>32</b> of the area <b>12</b>. This could be accomplished by pre-mapping (e.g., pre-drawing or pre-configuring) the map <b>32</b> of the area <b>12</b>. In the alternative, the computer system <b>30</b> can access a database to download the map <b>32</b> of the area <b>12</b>. The map <b>32</b> can include a variety of desired locations within the area <b>12</b>. For instance, the map <b>32</b> can display the paths, such as walkways, stairwells, doorways, etc. that exist in the area <b>12</b>. Furthermore, the map <b>32</b> can display any structures, exits out of the area <b>12</b>, and landmarks, such as the location of the control room, specific structures including machines, sensors, gauges, etc.

0025The specific locations of each of the RFID tags <b>8</b> could be included (e.g., preloaded) into the map <b>32</b> in advance. Specifically, a map of the area <b>12</b> could be stored that indicates the location of each of the RFID tags <b>8</b> along with the unique information of each of the RFID tags <b>8</b>. As such, the unique information (“RFID tag #<b>135</b>”) could be associated with a location of the specific RFID tag within the area <b>12</b>.

0026The RFID reader device <b>14</b> can further include a speaker <b>34</b>. The speaker can be in operative association with the computer system <b>30</b>, such that the computer system <b>30</b> can command the speaker <b>34</b> to emit sounds, warnings, alerts, words, sentences, etc. As such, the RFID reader device <b>14</b> can provide voice instructions/commands through the speaker <b>34</b>. The voice commands could be used in conjunction with the map <b>32</b>. For instance, in addition to showing the map <b>32</b>, the RFID reader device <b>14</b> could audibly state where the user is located, such as “next to the blast furnace and behind the steam pipe.” Furthermore, the RFID reader device <b>14</b> could audibly direct the user along a path and to a desired location by stating commands, such as “walk forward and turn left in 20 meters.”

0027Referring now to <figref idref="DRAWINGS">FIG. 3</figref>, the map <b>32</b> can be presented to a user of the RFID reader device <b>14</b> via a display screen <b>18</b> on the RFID reader device <b>14</b>. In one example, the computer system <b>30</b> can control the display screen <b>18</b> as a display output. For example, once the map <b>32</b> of the area <b>12</b> is preloaded to the computer system <b>30</b>, memory or the like, the computer system <b>30</b> can operate so that a map image is displayed on the screen <b>18</b>. The map <b>32</b> on the display screen <b>18</b> can be substantially identical to a layout of the area <b>12</b>. The display screen <b>18</b> can take on a number of sizes and configurations, depending on the specific RFID reader device <b>14</b> being used and/or the size of the area <b>12</b>.

0028It should be noted that the RFID reader device <b>14</b> can be integrated to and/or be a shared arrangement with a variety of other components/devices. For instance, the RFID reader device <b>14</b> could include a number of handheld devices, including, but not limited to, a cell phone, a smart phone, a mobile device, an iDevice, a GPS style locator, a wristwatch, etc. Accordingly, the user can use the handheld device, such as a cell phone, as the RFID reader device <b>14</b>. In these examples, some structures (e.g., the display screen <b>18</b>) could be commonly shared by multiple functions/features of the integrated/shared arrangement.

0029Referring now to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the operation of the guidance location system <b>10</b> can now be described. A user can have the RFID reader device <b>14</b> within the area <b>12</b>. The user may be lost, may need to know his/her current location, and/or may need guidance to a specific location within the area <b>12</b>, such as the exit. The user can prompt the RFID reader device <b>14</b>, such as by pressing a button, touching the display screen <b>18</b>, etc., to send out one or more signals <b>40</b>. For instance, the user could press a button on the RFID reader device <b>14</b> instructing the computer system <b>30</b> to cause emittance of one or more of the signals <b>40</b> from the RF transmitter <b>26</b>. The one or more signals <b>40</b> can pass through part or all of the area <b>12</b> and may be received by some or all of the antennas of the RFID tags <b>8</b>.

0030Each of the RFID tags <b>8</b> that receive the signal(s) <b>40</b> from the RFID reader device <b>14</b> can respond by transmitting the respective response signal <b>42</b> back to the RFID reader device <b>14</b>. Specifically, each receiving RFID tag <b>8</b> can each respond by transmitting the unique information specific to the RFID tag <b>8</b> back to the RFID reader device <b>14</b> via the signal <b>42</b>. As stated above, the unique information can be pre-programmed to the RFID tags <b>8</b> and can include a variety of information, such as the specific location of the RFID tag <b>8</b> within the area <b>12</b>. In the alternative, the unique information can include an identification of the RFID tag, such as “RFID tag #<b>135</b>”, or the like, that is associated with the specific location of the RFID tag <b>8</b> within the area <b>12</b>.

0031The RF receiver <b>28</b> of the RFID reader device <b>14</b> can receive the response signal(s) <b>42</b> from the RFID tags <b>8</b>. The unique information from the response signal(s) <b>42</b> can pass from the RF receiver <b>28</b> to the computer system <b>30</b> of the RFID reader device <b>14</b>. The computer system <b>30</b> can analyze and compare a variety of features of the response signals <b>42</b> to determine the current location of the RFID reader device <b>14</b>. For instance, the computer system <b>30</b> can analyze the time of response from the RFID tags <b>8</b>. Specifically, the time of response can be analyzed by the computer system <b>30</b> tracking the time between sending the signal <b>40</b> from the RF transmitter <b>26</b> and receiving a signal <b>42</b> in the RF receiver <b>28</b> from the RFID tags <b>8</b>. A longer time between the sending and receiving can indicate that an RFID tag <b>8</b> is farther away in proximity than an RFID tag <b>8</b> with a shorter time between the sending and receiving. The computer system <b>30</b> can analyze and compare each of the response signals <b>42</b> received by the RF receiver <b>28</b>.

0032The computer system <b>30</b> can further analyze the strength of the response signal <b>42</b> from the RFID tags <b>8</b> to determine the current location of the RFID reader device <b>14</b>. Specifically, the strength of the response signal <b>42</b> can be analyzed by the computer system <b>30</b> tracking the strength of the response signals <b>42</b> from the RFID tags <b>8</b>. A response signal <b>42</b> from an RFID tag <b>8</b> that has a stronger signal will be closer in proximity to the RFID reader device <b>14</b> than a response signal <b>42</b> from an RFID tag <b>8</b> that has a weaker signal. Any signals that reflect off of walls, structures, or the like may have a weaker signal and/or will come in phase shifted. The computer system <b>30</b> can determine whether a response signal <b>42</b> is an actual signal from the RFID tags <b>8</b>, or is a reflection and, thus, can be overlooked. The computer system <b>30</b> can analyze and compare these features of each of the response signals <b>42</b> sent by the RFID tags <b>8</b>. Based on the time of response of the response signals <b>42</b>, the strength of the response signals <b>42</b>, and the specific locations of the RFID tags <b>8</b>, the computer system <b>30</b> can triangulate an approximate location of the RFID reader device <b>14</b> within the area <b>12</b>. It is to be understood that further methods of determining the location of the RFID reader device <b>14</b> are contemplated. In one example, an angle of arrival (AoA) measurement can be used with the above described methods to determine the RFID reader device <b>14</b> location. For an AoA measurement, the computer system <b>30</b> can further analyze the time and direction of the response signal <b>42</b> on the RF receiver <b>28</b> by measuring a difference in received phase of the response signal <b>42</b> at the RF receiver <b>28</b>. A delay of arrival of the response signal <b>42</b> can be measured and converted to an AoA measurement, which can then be used to determine an approximate location of the RFID reader device <b>14</b>.

0033Referring now to <figref idref="DRAWINGS">FIG. 3</figref>, an example of the display screen <b>18</b> of the RFID reader device <b>14</b> is shown. Once the computer system <b>30</b> has determined the current location of the RFID reader device <b>14</b>, the computer system <b>30</b> can display the current location <b>37</b> of the RFID reader device <b>14</b> and thus the location of the user. Specifically, the computer system <b>30</b> can display the user's current location <b>37</b> on the map <b>32</b> on the display screen <b>18</b>. The computer system <b>30</b> will have determined the current location <b>37</b> with reference to the RFID tags <b>8</b>, such as 10 feet south of a first RFID tag and 4 feet west of a second RFID tag. Accordingly, the computer system <b>30</b> can display this current location <b>37</b> on the map <b>32</b> with an identifying signal, such as an X (as shown), or the like. Furthermore, the computer system <b>30</b> can chart a path <b>50</b> from the user's current location <b>37</b> to a desired location (e.g., an exit) <b>36</b>. As such, the user can look at the display screen <b>18</b> to guide the user from a current location <b>37</b> to the desired location (e.g., the exit) such as by highlighting a path. The display screen <b>18</b> can also display a distance to a next action in the form of text on the display screen <b>18</b>. For instance, the display screen <b>18</b> can display the distance from the user's current location <b>37</b> to a desired location, such as by displaying the text “turn left in 20 feet”, or the like.

0034As stated above, the map <b>32</b> is a map of the area <b>12</b> which includes paths, such as stairwells, walkways, etc., and locations, such as exits, landmarks, etc. Accordingly, the user can select the desired location <b>36</b> that he/she would like to reach, such as the exit. This could be accomplished by touching the display screen <b>18</b> if the RFID reader device <b>14</b> incorporates a touchscreen feature. In the alternative, the user could input the desired location <b>36</b> by manually selecting the location on the map <b>32</b>, such as by using buttons on the RFID reader device <b>14</b>, or the like. Once the desired location <b>36</b> is selected, the map <b>32</b> can display the user's current location <b>37</b> along with the path <b>50</b> from the user's current location <b>37</b> to the desired location <b>36</b>, such as the exit.

0035Referring now to <figref idref="DRAWINGS">FIG. 4</figref>, an example of the display screen <b>18</b> of the RFID reader device <b>14</b> is shown in an emergency escape mode. In this example, the RFID reader device <b>14</b> may have access to a wireless network. In this situation, sensors <b>38</b> may be provided within the area <b>12</b>. The sensors <b>38</b> can be shown on the map <b>32</b>, and can communicate with the RFID reader device <b>14</b> through the wireless network. The sensors <b>38</b> are generically shown, and can include a variety of danger sensing devices, such as fire alarms, smoke detectors, carbon monoxide detectors, radiation and/or temperature sensors, other types of danger detection systems, etc. The sensors <b>38</b> can determine the presence of a hazard <b>39</b>, such as a fire, gas leak, etc. The sensors <b>38</b> can communicate the presence and location of the hazard <b>39</b> through the wireless network to the RFID reader device <b>14</b>. As such, the computer system <b>30</b> can take into account the sensors <b>38</b> and hazard <b>39</b> when charting the path <b>50</b>.

0036The operation of the guidance location system <b>10</b> can now be described in the emergency escape mode. In the event of a hazard <b>39</b>, such as a fire, the sensors <b>38</b> can communicate with the RFID reader device <b>14</b> by alerting the RFID reader device <b>14</b> of the presence of a fire. The RFID reader device <b>14</b> can display a hazard indicator, such as a picture of a fire, on the map <b>32</b> at an approximate location of the hazard <b>39</b>. It is to be understood that the hazard indicator, while shown as a picture of a fire, could include any number of warning indications, and is not limited to the shown example. The computer system <b>30</b> can chart a path to the desired location <b>36</b>, such as the nearest exit, that avoids the hazard <b>39</b>. Additionally, the RFID reader device <b>14</b> can audibly warn the user of the dangerous situation by issuing a voice command <b>41</b> through the speaker <b>34</b> (see <figref idref="DRAWINGS">FIG. 2</figref>). The voice command <b>41</b> (<figref idref="DRAWINGS">FIG. 4</figref>) could issue a variety of warnings, such as “Fire near the blast furnace, proceed to nearest exit.” The emergency escape mode described herein can occur automatically once a dangerous situation arises. For instance, once the hazard <b>39</b> begins, the sensors <b>38</b> can immediately alert the RFID reader device <b>14</b>. Accordingly, the RFID reader device <b>14</b> can instantly issue the voice command <b>41</b> and chart the path <b>50</b> to the nearest exit.

0037In a further example, a remote location, such as a centralized server, could also read and communicate with the sensors <b>38</b> and/or the RFID reader device <b>14</b>. The sensors <b>38</b> and/or the RFID reader device <b>14</b> can communicate with the centralized server to alert the centralized server of the presence of the hazard <b>39</b> and/or the location of the RFID reader device <b>14</b>. The centralized server could communicate with the RFID reader device <b>14</b> to alert the RFID reader device <b>14</b> of the presence and location of the hazard <b>39</b>. The computer system <b>30</b> could chart a path to the desired location <b>36</b>, such as the nearest exit, that avoids the hazard <b>39</b>. In this example, the sensors can communicate with both the centralized server and RFID reader device <b>14</b>. Accordingly, if wireless communication between the centralized server and the RFID reader device <b>14</b> is inoperable for some reason, the RFID reader device <b>14</b> could still communicate directly with the sensors <b>38</b>. Similarly, the current location of the RFID reader device <b>14</b> can be sent to the remote location, including the centralized server, such that a 3^rdparty can monitor and/or track the location of the RFID reader device <b>14</b> within the area <b>12</b> from the remote location.

0038The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Example embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.