KR20070061111A - Apparatus and method of recognition of position to minimize the consumption of electric power in the sensor networking environment - Google Patents

Abstract

An apparatus and a method of recognizing a position for minimizing power consumption in a sensor network environment are provided to continuously recognize the position in spite of expansion of a system through auto beaconing of a semi-automatic type. A method of recognizing a position for minimizing power consumption in a sensor network environment includes the steps of: calculating initial position coordinates with beacon information received from adjacent beacons through a broadcasted beacon solicitation signal, transmitting a synchronizing signal to the corresponding beacons, and synchronizing the signal(S100); receiving supersonic waves generated in the adjacent beacons activated through a broadcasted start message, and calculating position coordinates(S200); and transmitting a handoff processing message to a newly activated beacon if the calculated position coordinates exist at a pre-set handoff critical position, and performing a handoff processing routine(S300).

Description

Apparatus and method of recognition of position to minimize the consumption of electric power in the sensor networking environment}

1 is a view showing the structure of the position recognition device in the sensor network environment according to the present invention

2 is a flow chart illustrating a location recognition method in a sensor network environment according to the present invention.

* Explanation of symbols for main parts of the drawings

10: receiver 20: beacon

The present invention relates to ubiquitous computing, and more particularly, to a location recognition device and method for minimizing power consumption in a sensor network environment.

Recently, research on ubiquitous computing has been in the spotlight. Ubiquitous computing can recognize the situation of the surrounding space and provide an intelligent environment that provides the right user or user device with the necessary information at the right time based on the recognized situation.

This is made possible by the incorporation of a tiny, intelligent, embedded computer with a communication device in the surrounding objects and environment to form a mutual network. Therefore, even if users are physically separated from each other, it means that the user can receive a context-aware and specialized information service by recognizing or tracking the change of objects and the surrounding environment according to a desired place or time.

In order for an intelligent object or environment to provide an appropriate service according to a user's situation, the physical location and condition of the user or user device and the degree of change thereof must also be recognized. Therefore, the user's location information will be a very important element for the context-aware service that will be provided in the ubiquitous computing environment.

Representative systems for acquiring the user's location information include a GPS (Global Positioning System) and a location measurement system using a mobile communication network. In particular, GPS has been widely used due to the advantages of more accurate position measurement and use in all the places of the earth than the position measurement system using a mobile communication network.

However, due to the characteristics of the GPS requiring a line of sight (ROS), it is difficult to use indoors, and precise position measurement requiring an error range of several tens of cm or less has a disadvantage. In addition, in the ubiquitous computing environment where embedded computers are used in the surrounding environment and things, the price of the device is a very important factor, so the relatively expensive GPS is not suitable. On the other hand, in a particular region where the range is limited as in the case of indoors, relative position information such as how far from the reference position may be more useful than absolute position information expressed by latitude and longitude.

In view of the above, there is a need for a new positioning system that can replace the GPS which is widely used outdoors, and thus, a low-cost positioning system that can be installed in a user's device or a sensor node to determine a relative position. The invention about is actively progressing.

Accordingly, an object of the present invention is to provide an inexpensive position recognition device and method that can be used indoors and that enables precise position measurement.

Another object of the present invention is to provide an apparatus and method for recognizing a location which can improve energy efficiency by reducing unnecessary power consumption by minimizing RF and ultrasonic waves periodically generated in a wireless sensor network.

The feature of the location recognition method for minimizing power consumption in the sensor network environment according to the present invention for achieving the above object is (a) the initial zone with beacon information received from adjacent beacons through the broadcast beacon guidance signal Calculating position coordinates, sending synchronization signals to corresponding beacons, and synchronizing; (b) calculating position coordinates by receiving ultrasonic waves generated from adjacent activated beacons through a broadcast start message; (c) transmitting the handoff processing message to a newly activated beacon and performing a handoff processing routine when the calculated position coordinate exists at a threshold for setting a preset handoff zone.

Preferably, the step (a) comprises: (a1) broadcasting a beacon solicitation signal, which is an RF signal, and transmitting the signal to a beacon fixed to an adjacent position; and (a2) the beacon of the corresponding beacon receiving the beacon induction signal. Receiving information and calculating an initial zone position coordinate of the receiver; and (a3) synchronizing by transmitting a synchronization signal to the beacons and receiving ultrasonic waves according to an acknowledgment in the beacons.

Preferably, the step (b) includes: (b1) periodically broadcasting a start message, which is an ultrasonic signal, to activate adjacent beacons, and (b2) numbered beacons after synchronization is performed through time compensation of the activated beacons; Receiving ultrasonic waves generated in the allocated time intervals according to the order of the IDs; and (b3) obtaining distance information using time arrival information between the receiver and the beacon through the received ultrasonic waves, and then the user device and the situation recognition server. And transmitting the position coordinates to update the position.

Preferably, the step (b1) further comprises the step of switching the beacon to the power saving mode state in which the start message is not received for a predetermined time.

Preferably, the position coordinate calculation of step (b3) monitors a serial interface and parses three distance values if there is data from the receiver, and parses each of the parsed distance values into a position coordinate calculation algorithm. Acquiring position coordinates and displaying the position coordinates in a GUI.

Preferably, the step (c) comprises: (c1) setting a threshold position for handoff zone setting in consideration of the ultrasonic reach area of each beacon, and (c2) calculated at the set handoff threshold position. Transmitting a handoff processing message to a newly activated beacon when the position coordinate is located; and (c3) broadcasting a beacon solicitation signal with RF to the corresponding beacon 20 and performing a handoff processing routine. Characterized in that it comprises a.

Preferably, the handoff processing message is characterized in that the beacon includes information to wait without transmitting in the time interval to transmit the ultrasound.

Preferably, the threshold position for setting the handoff zone (c1) may be set based on the ultrasonic region of the beacon having the same Numbered ID as the beacon in which the ultrasonic wave is received but having a unique ID.

Preferably, step (c4) further includes a step in which the beacon receiving the beacon guidance signal is received in response thereto, and performing synchronization with the system so that synchronization is not deviated through periodic updating.

Preferably, when the initialization step is completed, the corresponding beacons are maintained in a standby state.

) 정보 또는 활성화 정보를 포함하는 것을 특징으로 한다.Preferably, the start message includes a time interval according to the synchronization information and the sequence of the numbered ID of each beacon.

) Information or activation information.

Preferably, the activation information is characterized by including the unique ID of each beacon.

A feature of the position recognition device for minimizing power consumption in the sensor network environment according to the present invention for achieving the above object is a plurality of beacons are installed at a fixed position at a predetermined interval to transmit RF signals and ultrasonic signals ( beacon) and receiving a RF signal and an ultrasonic signal capable of positional change and transmitting from the beacon, and generating position measurement information on the changed position using the difference in the reception time, the reception time information, and the RF signal. It includes the receiver.

Preferably, a user device that provides a position coordinate calculation and a calculated position coordinate GUI (Graphic User Interface) function by using the information generated by the receiver, and detects the user's position by connecting to a serial interface to the ubiquitous through the external terminal Characterized in that it further comprises a situation-aware server that provides a service.

Preferably, the beacon is configured as a sensor node having two or more address information, such as a unique ID and a numbered ID.

Preferably, the unique ID depends on the number of beacons constituting the system, and the Numbered ID is sequentially assigned from 0 to 3 times regardless of the number of beacons constituting the system.

Preferably, the beacon is a predetermined interval between neighboring beacons are characterized in that less than 5m.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments with reference to the accompanying drawings.

The present invention according to the present invention will be described below with reference to the accompanying drawings, a preferred embodiment of the position recognition method for minimizing power consumption in the sensor network environment.

1 is a view showing the structure of the position recognition device in the sensor network environment according to the present invention.

As shown in FIG. 1, a plurality of beacons 20 are installed at fixed positions at predetermined intervals to transmit RF signals and ultrasonic signals, and RF signals transmitted from the beacons 20 are capable of changing positions. The receiver 10 is configured to receive an ultrasonic signal, and generate position measurement information on a position changed using the difference in the reception time, the reception time information, and the RF signal.

In addition, a user device providing a position coordinate calculation and a calculated position coordinate GUI (Graphic User Interface) function using the information generated by the receiver 10 and a terminal connected to a serial interface by identifying a user's position. It is additionally configured as a situation-aware server that provides ubiquitous service.

The beacon 20 uses a sensor node having two or more address information, such as a unique ID and a numbered ID, together with its own position coordinates. At this time, the unique ID is different depending on the number of beacons 20 constituting the system, the numbered ID is preferably assigned sequentially from 1 to 4 times irrespective of the number of beacons constituting the system.

In addition, the predetermined interval between neighboring beacons 20 is preferably not more than 5m in consideration of the transmission and reception between the receiver 10 and the beacons 20 through RF and ultrasonic waves.

The operation of the position recognition method for minimizing power consumption in the sensor network environment according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

2 is a flowchart illustrating a location recognition method in a sensor network environment according to the present invention.

As shown in FIG. 2, first, when the receiver 10 is powered on, the receiver 10 sends a broadcasting packet according to a beacon solicitation message to the RF to make the beacon 20 in an adjacent position to the ultrasonic interrupt standby state. . In this case, the beacon guidance message is only received by the beacons 20 located in the limited area in the transmitted RF region.

On the other hand, the beacon 20 waits in the standby state when the power is turned on, when receiving the beacon guidance message from the receiver 10 transmits its position coordinates, unique ID and Numbered ID from the receiver 10 and back to the dashed state Enter At this time, the beacons which do not receive the beacon guidance message continue to remain in a standby state.

Then, the receiver 10 calculates its initial position coordinate through the transmitted beacon information (S110). In addition, the beacon 20 having a corresponding unique ID is called for synchronization, and a synchronization signal (Sync) is transmitted to the beacons. Accordingly, the beacon 20 generates an ultrasonic wave to the receiver 10 and notifies the reception confirmation to end the initial process for synchronization (S100).

At this time, when the initialization process is completed, the beacons enter a standby state.

When the initial process for synchronization is completed and the initial position coordinates of the receiver are calculated, the receiver 10 broadcasts a start message for initiating beacon scheduling for automatic position recognition.

) 정보 및 활성화 정보가 포함되어 있다. The start message includes a time interval according to the synchronization information of the receiver 10 and the numbered ID order of each beacon 20.

) And activation information.

At this time, the receiver synchronization information is used to allow the beacons of the system to synchronize with the receiver.

)

이다. The time interval information (

)

to be.

: 초음파 도달시간, 그리고

리시버의 거리 값 계산 프로세스 처리 시간을 나타낸다.In this case, n: Numbered ID, n = 0, 1, 2, 3,

Ultrasound arrival time, and

Indicates the processing time of the distance value calculation process of the receiver

Since one round of beacon 20 has 4 numbered IDs, all beacons having 4 numbered IDs transmit ultrasonic waves sequentially according to the numbered IDs, and the receiver calculates the distance value as the sum of the 4 time interval information. After one round of time, the user device or situation awareness server can calculate the position coordinates of the receiver.

)은

이다.Full round time (

)silver

to be.

Subsequently, activation information included in the start message designates unique IDs of beacons necessary for calculating location information when the receiver knows the current location on the application map as an initialization process.

When the start message is broadcast in the receiver 10 as described above, the beacons 20 present in the ultrasonic region of the receiver 10 are activated (S210).

The beacons 20 activated in this manner perform synchronization through their time compensation through the synchronization information of the start message (S220), and then apply ultrasonic waves to the allocated time intervals according to the order of the numbered IDs they have. Generate.

Conventionally, the present invention recognizes the beacon 20 using a pair of RF and ultrasonic waves, so the beacons 20 are activated through a start message. Therefore, the beacon 20 easily generates ultrasonic waves without using RF. It becomes possible.

As a result, the receiver 10 does not generate RF for calling the unique ID of the beacon 20 each time and uses the broadcasting packet according to the beacon solicitation message in the initial process and periodically synchronizes the synchronization message. RF is used only when used, saving radio resources and power. It also greatly reduces the probability of collisions or latency between radios when routing or exchanging necessary information.

In addition, the beacons 20 whose unique IDs do not correspond to activation enter a power saving mode with only an ultrasonic reception interrupt applied to minimize power consumption. Then, when the ultrasonic wave is received from the receiver 10, the ultrasonic wave is switched from the power saving mode to the active state by the interrupt and participates in the automatic location recognition process using the existing synchronization information (S200).

As such, the beacons 20 entering the power saving mode and the beacons 20 in the activated state are switched according to the presence or absence in the ultrasonic zone periodically transmitted from the receiver 10.

That is, the ultrasonic wave periodically transmitted from the receiver 10 converts the beacon 20 positioned in the corresponding area into an active state by moving the position of the receiver 10. In addition, when the beacons 20 in the activated state do not receive the ultrasonic waves of the periodic receiver 10, it is determined that the position recognition is unnecessary, and the state is switched back to the power saving mode state and waits for a new ultrasonic reception interrupt.

As described above, the receiver 10 obtains continuous distance information between the beacons 20 and transmits it to the user device and the situation recognition server to update the position coordinates of the receiver 10 (S230).

In this case, the user device PDA or LAPTOP provides a position coordinate calculation and a calculated position coordinate GUI (Graphic User Interface) function. Therefore, the user device monitors the serial interface and parses the data into three distance values if there is data from the receiver 10. Each parsed distance value is input to the position coordinate calculation algorithm to calculate the position coordinates of the user device and display it on the GUI.

In addition, it monitors whether the position coordinates of the receiver 10 calculated on the application map exist at a critical position for the predetermined handoff zone setting, and when the event occurs, the receiver 10 is serially informed of the possibility of handoff. The message will be sent serially.

In addition, the situation awareness server connects the sink node communicating with the receiver 10 by RF through a serial interface. And the situation recognition server has a location calculation algorithm and GUI of the same type as the user device. Therefore, the distance information with the beacon 20 transmitted from the receiver 10 to the RF is input to the position calculation algorithm of the situation recognition server through the sink, and is displayed through the GUI when calculating the position coordinates of the user.

The difference between the situation recognition server and the user device is that the situation recognition server can detect the location of the user and provide a ubiquitous service without user intervention.

Through this, the position of the current receiver 10 is recognized (S200).

Then, when the synchronization request message from the receiver 10 arrives at another beacon 20 newly entered through the movement of the receiver 10, the beacon 20 responds and synchronizes with the system through periodic updates. Do not allow to slip.

Since the present invention is based on scalability support for a large service, handoff processing is required.

Since the receiver 10 knows the map of the system by the application of the user device, it is possible to set the handoff threshold position in consideration of the ultrasonic arrival zone of each beacon 20. Therefore, the criterion for setting the handoff threshold position is made by determining whether the unique ID goes to an ultrasonic zone of another beacon although the same numbered ID is used as the beacon 20 generating the ultrasonic waves received at the receiver's current position.

That is, if the position continuously changing and displayed on the application map is directed to the handoff threshold position, the receiver 10 uses the RF to beacon 20 of the current position having the same value as that of the Numbered ID which is likely to receive ultrasonic waves in the future. Transmits a handoff processing message destined for the unique ID.

If the beacon 20 to which the handoff processing message is transmitted receives the ultrasound in the time interval in which the ultrasound is to be transmitted, it means that the receiver 10 has been handed off to the next area beyond the handoff threshold position.

Therefore, if the ultrasound transmitted from the receiver 10 is not received until the next time interval of the corresponding beacon 20 having the unique ID, it does not occur because the receiver 10 has returned from the handoff threshold position. It means no.

On the contrary, if a broadcasting packet according to a beacon solicitation message is transmitted from the receiver 10 to the corresponding beacon 20 in RF in the corresponding time interval, it is determined that the handoff has occurred and the handoff processing is performed. Perform the routine (S310).

As described above, the preferred embodiment of the present invention has been disclosed through the detailed description and the drawings. The terms are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Location recognition apparatus and method for minimizing power consumption in the sensor network environment according to the present invention as described above has the following effects.

First, it uses semi-automatic auto beaconing triggered by the receiver rather than beacon scheduling based on the custom round robin method of the receiver of the existing system. It is possible.

Second, by minimizing the RF and ultrasonic waves that occur periodically in the wireless sensor network, unnecessary power consumption can be reduced, leading to a significant reduction in power consumption compared to existing systems. In addition, since the RF transmission is minimized, the additional effect is to minimize the probability of RF collision in the system.

Third, beacons that are unnecessary for location recognition when viewed from the current location on the application map can be put into power saving mode using activation information included in the start message, thereby minimizing RF resource usage and minimizing power consumption of the entire system.

Fourth, since most of the waves that occupy the media inside the system are ultrasonic waves that contain no information, there is no need to consider the beacon collision problem even if the system is expanded.

Claims (18)

(a) an initialization step of calculating initial position coordinates from beacon information received from adjacent beacons through a broadcast beacon guidance signal, and sending a synchronization signal to the beacons to synchronize with each other; (b) receiving the ultrasound generated from the adjacent beacons activated through the broadcast start message to calculate the position coordinates; and (c) transmitting a handoff processing message to a newly activated beacon and performing a handoff processing routine when the calculated position coordinate exists at a preset handoff threshold position. The method of claim 1, wherein step (a) (a1) broadcasting a beacon solicitation signal, which is an RF signal, and transmitting the signal to a beacon fixed at an adjacent position; (a2) receiving beacon information of the corresponding beacon which has received the beacon guidance signal and calculating initial position coordinates of a receiver; and (a3) synchronizing by transmitting a synchronization signal to the beacons and receiving ultrasonic waves according to an acknowledgment in the beacons. The method of claim 1, wherein step (b) (b1) periodically broadcasting a start message, which is an ultrasonic signal, to activate adjacent beacons; (b2) receiving an ultrasonic wave generated in an allocated time interval according to the order of the numbered ID of the beacon after synchronization through time compensation of the activated beacons is performed; and (b3) calculating distance coordinates by updating distance information between a receiver and a beacon through the received ultrasound and transmitting the distance information to a user device and a situation recognition server. The method of claim 3, wherein Wherein (b1) is a location recognition method further comprises the step of switching the beacons do not receive a start message to the power saving mode state. The method of claim 3, wherein the calculation of the position coordinates of step (b3) Monitoring the serial interface, reading data from the receiver, parsing it into three distances, Inputting each parsed distance value to a position coordinate calculation algorithm to calculate a position coordinate and display the same in a GUI. The method of claim 1, wherein step (c) (c1) setting a handoff threshold position in consideration of the ultrasonic arrival zone of each beacon; (c2) if the calculated position coordinate is located at the set handoff threshold position, transmitting a handoff processing message to a newly activated beacon; (c3) broadcasting a beacon solicitation signal in RF to the corresponding beacon (20) and performing a handoff processing routine. The method of claim 6, The handoff threshold position of (c1) has the same Numbered ID as the beacon in which the ultrasound is received, but the unique ID is set based on the ultrasonic zone of the beacon different. The method of claim 6, The step (c4) further comprises the step of responding to the beacon receiving the beacon guidance signal is received, and performing a synchronization with the system so that the synchronization is not out of sync through the periodic update. The method of claim 1, When the initialization step is finished, the beacons are maintained in a standby state. The method of claim 1, Position recognition method characterized in that the transmission and reception of any one of the RF signal or ultrasonic signal. The method of claim 1, The beacon information location recognition method comprising the position coordinates, unique ID or Numbered ID of the beacon. The method of claim 1, The start message includes time information according to the synchronization information and the sequence of the numbered ID of each beacon.

) Location recognition method comprising the information or activation information. The method of claim 12, The activation information comprises a unique ID of each beacon. A plurality of beacons (beacons) are provided at fixed positions at predetermined intervals to transmit RF signals and ultrasonic signals, And a receiver capable of changing the position and receiving an RF signal and an ultrasonic signal transmitted from the beacon, and generating position measurement information on the changed position using the difference in the reception time, the reception time information, and the RF signal. Locator device configured. The method of claim 14, A user device for providing a position coordinate calculation and a calculated position coordinate GUI (Graphical User Interface) function using the information generated by the receiver; Location recognition device further comprises a situation-aware server that detects the location of the user and connects to the serial interface to provide ubiquitous service through the terminal to the outside. The method of claim 14, The beacon is a location recognition device consisting of a sensor node having two or more address information, such as a Unique ID and Numbered ID. The method of claim 16, The unique ID is dependent on the number of beacons constituting the system, and the Numbered ID is sequentially assigned from 1 to 4 times irrespective of the number of beacons constituting the system. The method of claim 14, The beacon is a location recognition device, characterized in that the predetermined interval between neighboring beacons 5m or less.

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