1. Field of the Invention
The 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.
2. Discussion of Prior Art
Global 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.
The 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.
In 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.
In 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.
The 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:
Example 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.
The area 12 (
Referring still to
The RFID tags 8 can be attached to or at least placed proximate to the structures 20. In one example methodology, the RFID tags 8 can be removably affixed to the structures 20 in a number of ways, including by adhesives, snap fit means, or the like. Accordingly, when the RFID tags 8 are positioned on the structures 20, the RFID tags 8 and will remain fixed to the structures 20 unless removed. The RFID tags 8 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 8 can effectively be used in a variety of environments, including high and low temperature environments, environments with high moisture and humidity, etc.
Referring now to
Turning to possible physical specifics of the RFID tags 8, 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 14. Specifically, a passive RFID tag utilizes electromagnetic field properties of the communication from the RFID reader device 14 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 14 similar to the passive RFID.
In the shown example of
It should be noted again that the RFID tags 8 in the present example are not limited to the RFID tag shown and described with regard to
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The signals 40 and 42 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 42 can be received by any of the plural RFID tags 8 (
The RF transmitter 26 and the receiver 28 can be controlled by a computer system 30 (
The specific locations of each of the RFID tags 8 could be included (e.g., preloaded) into the map 32 in advance. Specifically, a map of the area 12 could be stored that indicates the location of each of the RFID tags 8 along with the unique information of each of the RFID tags 8. As such, the unique information (“RFID tag #135”) could be associated with a location of the specific RFID tag within the area 12.
The RFID reader device 14 can further include a speaker 34. The speaker can be in operative association with the computer system 30, such that the computer system 30 can command the speaker 34 to emit sounds, warnings, alerts, words, sentences, etc. As such, the RFID reader device 14 can provide voice instructions/commands through the speaker 34. The voice commands could be used in conjunction with the map 32. For instance, in addition to showing the map 32, the RFID reader device 14 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 14 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.”
Referring now to
It should be noted that the RFID reader device 14 can be integrated to and/or be a shared arrangement with a variety of other components/devices. For instance, the RFID reader device 14 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 14. In these examples, some structures (e.g., the display screen 18) could be commonly shared by multiple functions/features of the integrated/shared arrangement.
Referring now to
Each of the RFID tags 8 that receive the signal(s) 40 from the RFID reader device 14 can respond by transmitting the respective response signal 42 back to the RFID reader device 14. Specifically, each receiving RFID tag 8 can each respond by transmitting the unique information specific to the RFID tag 8 back to the RFID reader device 14 via the signal 42. As stated above, the unique information can be pre-programmed to the RFID tags 8 and can include a variety of information, such as the specific location of the RFID tag 8 within the area 12. In the alternative, the unique information can include an identification of the RFID tag, such as “RFID tag #135”, or the like, that is associated with the specific location of the RFID tag 8 within the area 12.
The RF receiver 28 of the RFID reader device 14 can receive the response signal(s) 42 from the RFID tags 8. The unique information from the response signal(s) 42 can pass from the RF receiver 28 to the computer system 30 of the RFID reader device 14. The computer system 30 can analyze and compare a variety of features of the response signals 42 to determine the current location of the RFID reader device 14. For instance, the computer system 30 can analyze the time of response from the RFID tags 8. Specifically, the time of response can be analyzed by the computer system 30 tracking the time between sending the signal 40 from the RF transmitter 26 and receiving a signal 42 in the RF receiver 28 from the RFID tags 8. A longer time between the sending and receiving can indicate that an RFID tag 8 is farther away in proximity than an RFID tag 8 with a shorter time between the sending and receiving. The computer system 30 can analyze and compare each of the response signals 42 received by the RF receiver 28.
The computer system 30 can further analyze the strength of the response signal 42 from the RFID tags 8 to determine the current location of the RFID reader device 14. Specifically, the strength of the response signal 42 can be analyzed by the computer system 30 tracking the strength of the response signals 42 from the RFID tags 8. A response signal 42 from an RFID tag 8 that has a stronger signal will be closer in proximity to the RFID reader device 14 than a response signal 42 from an RFID tag 8 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 30 can determine whether a response signal 42 is an actual signal from the RFID tags 8, or is a reflection and, thus, can be overlooked. The computer system 30 can analyze and compare these features of each of the response signals 42 sent by the RFID tags 8. Based on the time of response of the response signals 42, the strength of the response signals 42, and the specific locations of the RFID tags 8, the computer system 30 can triangulate an approximate location of the RFID reader device 14 within the area 12. It is to be understood that further methods of determining the location of the RFID reader device 14 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 14 location. For an AoA measurement, the computer system 30 can further analyze the time and direction of the response signal 42 on the RF receiver 28 by measuring a difference in received phase of the response signal 42 at the RF receiver 28. A delay of arrival of the response signal 42 can be measured and converted to an AoA measurement, which can then be used to determine an approximate location of the RFID reader device 14.
Referring now to
As stated above, the map 32 is a map of the area 12 which includes paths, such as stairwells, walkways, etc., and locations, such as exits, landmarks, etc. Accordingly, the user can select the desired location 36 that he/she would like to reach, such as the exit. This could be accomplished by touching the display screen 18 if the RFID reader device 14 incorporates a touchscreen feature. In the alternative, the user could input the desired location 36 by manually selecting the location on the map 32, such as by using buttons on the RFID reader device 14, or the like. Once the desired location 36 is selected, the map 32 can display the user's current location 37 along with the path 50 from the user's current location 37 to the desired location 36, such as the exit.
Referring now to
The operation of the guidance location system 10 can now be described in the emergency escape mode. In the event of a hazard 39, such as a fire, the sensors 38 can communicate with the RFID reader device 14 by alerting the RFID reader device 14 of the presence of a fire. The RFID reader device 14 can display a hazard indicator, such as a picture of a fire, on the map 32 at an approximate location of the hazard 39. 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 30 can chart a path to the desired location 36, such as the nearest exit, that avoids the hazard 39. Additionally, the RFID reader device 14 can audibly warn the user of the dangerous situation by issuing a voice command 41 through the speaker 34 (see
In a further example, a remote location, such as a centralized server, could also read and communicate with the sensors 38 and/or the RFID reader device 14. The sensors 38 and/or the RFID reader device 14 can communicate with the centralized server to alert the centralized server of the presence of the hazard 39 and/or the location of the RFID reader device 14. The centralized server could communicate with the RFID reader device 14 to alert the RFID reader device 14 of the presence and location of the hazard 39. The computer system 30 could chart a path to the desired location 36, such as the nearest exit, that avoids the hazard 39. In this example, the sensors can communicate with both the centralized server and RFID reader device 14. Accordingly, if wireless communication between the centralized server and the RFID reader device 14 is inoperable for some reason, the RFID reader device 14 could still communicate directly with the sensors 38. Similarly, the current location of the RFID reader device 14 can be sent to the remote location, including the centralized server, such that a 3rd party can monitor and/or track the location of the RFID reader device 14 within the area 12 from the remote location.
The 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.