KR20030018912A - Location search system and location search method using rf signal - Google Patents

Abstract

PURPOSE: A position tracking system and a method thereof are provided to calculate a distance to a radio frequency(RF) signal generator in order to exactly track a position of a transmitter. CONSTITUTION: An omnidirectional antenna(110) transmits or receives an RF signal in radio. The first switch section(120) connects the omnidirectional antenna(110) to one of an amplifier(160) or a response message demodulator(130). The response message demodulator(130) includes an amplifier(132) and a demodulator(134). The amplifier(132) amplifies a level of a received RF signal. The demodulator(134) demodulates and outputs the amplified RF signal to a response message to a microprocessor(140). The microprocessor(140) controls a total operation of an RF signal generator(100) according to a user command inputted through a user I/F(170). A signal generator(150) includes a continuous wave(CW) generator(152) and a modulator(154).

Description

LOCATION SEARCH SYSTEM AND LOCATION SEARCH METHOD USING RF SIGNAL

The present invention relates to a location tracking system, and more particularly, to a system and a method for tracking the location of an RF source by calculating a distance to a radio wave transmission point.

The location tracking system is a system that can be used to track the location of a moving object, and is widely used and applied in the field of anti-lost or mobile communication terminal tracking, theft vehicle tracking, and the defense industry.

A general location tracking system is composed of a transmitter and a receiver, and the receiver measures the magnitude of the signal transmitted from the transmitter and tracks the point where the signal is transmitted while correcting the direction of the antenna in the direction where the greatest power is detected. Has been used.

However, in the conventional location tracking system, since only the approximate location information of the point at which the signal is transmitted can be known, the distance to the precise origin can not be known, which has a disadvantage in that a lot of time is required for location tracking.

Accordingly, an object of the present invention is to provide a location tracking system and method for accurately tracking the location of an originating device by calculating the distance to the RF signal generator.

Still another object of the present invention is to provide a location tracking system and method for tracking a transmitting device quickly and accurately by calculating the distance of the RF signal generator.

1 is a configuration diagram of a location tracking system according to an embodiment of the present invention.

2 is a detailed configuration diagram of the RF signal generator 100 of FIG.

3 is a detailed configuration diagram of the RF signal receiving apparatus 200 of FIG.

4 is an operation flowchart of the microprocessor 140 of FIG. 2.

FIG. 5 is a flowchart of operation of the microprocessor 280 of FIG. 3.

6 is an exemplary diagram illustrating the relationship between the received power of the continuous wave CW and power detection data.

7 is an exemplary diagram illustrating a relationship between a phase difference between phases of received continuous waves (CW) and phase detection data.

8 is a view for explaining a distance calculation process to the RF signal generator 100 according to an embodiment of the present invention.

Position tracking system according to an embodiment of the present invention for achieving the above object is largely composed of an RF signal generator and an RF signal receiving device;

The RF signal generator, modulates a call message and transmits the radio by amplifying a continuous wave (CW) oscillated by the oscillator to a predetermined level when receiving a response message, and transmits the RF signal.

The RF signal receiving apparatus, when receiving a call message through the omni-directional antenna, modulates a response message in response to the radio transmission, and wirelessly receives the received power of the continuous wave (CW) received through two or more directional antennas rotating in conjunction with each other. Detects the phase difference between the continuous waves CW received through each of the directional antennas in the direction of maximum and calculates the distance L1 due to the phase difference, and rotates the antenna until the phase difference becomes zero in the antenna direction. It is characterized by substituting the rotation angle of α with the distance L1 in Equation 1 below to output the distance to the RF signal generator.

R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction.

Position tracking system according to another embodiment of the present invention,

An RF signal generator for amplifying a continuous wave (CW) oscillated by an oscillator to a predetermined level and transmitting the RF;

The distance by the phase difference is detected by detecting the phase difference between the continuous wave CW received through each of the directional antennas in the direction in which the reception power of the continuous wave CW received through the two directional antennas rotating in conjunction is maximum. L1 is calculated, and the angle of rotation of the antenna rotated until the phase difference becomes zero in the antenna direction is substituted into the following equation (2) together with the distance L1 to the RF signal generator. RF signal receiving apparatus for outputting a; characterized in that it comprises a.

R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction.

In addition, the method of the present invention for tracking the position of the target in the system for tracking the position of the target originating the continuous wave (CW),

Detecting a direction in which the reception power of the continuous wave CW received through two directional antennas rotating in association with each other is maximum;

Calculating a distance L1 due to a phase difference between the continuous waves CW received through each of the antennas in the direction of maximum reception power;

Detecting a rotation angle (α) of the antenna rotated until the phase difference becomes zero in the direction of the maximum reception power;

Calculating the distance (D) to the continuous wave (CW) transmission target by substituting the distance L1 and the antenna rotation angle α by the phase difference into the following Equation 2;

And outputting the calculated distance D to a display device or transmitting the calculated distance D to an external device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

First, FIG. 1 illustrates a schematic configuration of a location tracking system according to an exemplary embodiment of the present invention. The location tracking system includes a master RF signal generator 100 and a slave RF signal receiver 200. In the embodiment of the present invention, although the generator 100 is a master, the receiver 200 may be referred to as a master. If the RF signal generator 100 calls the receiver 200, the generator 100 may be referred to as a master, and simply tracks the position of the generator 100 on the receiver 200 side. This is because the receiver 200 can be viewed as a master.

Meanwhile, the RF signal receiving device 200 may be mounted in a defense industry or an industrial robot to automatically track the RF signal generating device 100. In this case, it is possible to implement by adding an interface unit that enables signal transmission between the main control unit of the RF signal receiving apparatus 100 and the control unit of the robot system, simply by the control unit of the robot system of the RF signal receiving apparatus 200 It may be designed to calculate the distance to the RF signal generator 100 performed by the microprocessor.

Hereinafter, the configurations of the above-described RF signal generator 100 and the receiver 200 will be described in detail.

FIG. 2 illustrates a detailed configuration diagram of the RF signal generator 100 of FIG. 1. The RF signal generator 100 is a continuous wave (CW) oscillated by an oscillator, unlike FIG. 1. May be designed to amplify a predetermined level to transmit RF.

Referring to FIG. 2, first, the omni directional antenna 110 performs a role of wirelessly transmitting or wirelessly receiving an RF signal, and the omni directional antenna 100 is an amplifier according to the switching operation of the first switching unit 120. It is connected to the output terminal of the 160 or the input terminal of the amplifier 132 which is one component of the response message demodulator 130.

The first switching unit 120 controls the switching operation according to a switch control signal output from the microprocessor 140 that controls the overall operation of the RF signal generator 100 so that the directional antenna 110 is connected to the amplifier 160. It performs the role of connecting to any one of the response message demodulator (130).

The response message demodulator 130 includes an amplifier 132 for amplifying the level of the received RF signal and a demodulator 134 for demodulating the amplified RF signal into a response message and outputting the demodulated message to the microprocessor 140. . The response message demodulator 130 may be referred to simply as a demodulator.

The microprocessor 140 generally controls the operation of the RF signal generator 100 according to a user command input through the user I / F 170. For example, in order to wirelessly transmit a call message, the first switching unit 120 is controlled after the omnidirectional antenna 110 is first connected to the amplifier 160, and then the first switching unit 120 is again controlled. To receive the response message. When the response message is received, it also plays a role of outputting a continuous wave control signal for oscillating the continuous wave CW.

The signal generator 150 includes a continuous wave generator 152 and a modulator 154. The continuous wave generator 152 may be configured as an oscillator. The continuous wave generator 152 is operation controlled according to the continuous wave control signal. The modulator 154 modulates and outputs a call message input from the microprocessor 140.

The amplifier 160 amplifies and outputs the level of the call message or the continuous wave CW modulated by the signal generator 150.

The user I / F unit (InterFace) 170 may include a key button for inputting a call command, an alarm unit, and a display unit. The key button is for inputting the occurrence of a call message, and the alarm unit is for notifying the user of an error condition when a response message is not received for a predetermined time after sending the call message, and the display unit is also for notifying an error condition and an operation condition. . Such a configuration is not an essential component and may be optionally configured.

As described above, the RF signal generating apparatus 100 modulates a call message and transmits the radio by amplifying a continuous wave (CW) oscillated by an oscillator to a predetermined level when receiving a response message. do. And it may be designed to simply amplify the continuous wave (CW) oscillated by the oscillator to a predetermined level to transmit the RF.

Meanwhile, FIG. 3 illustrates a detailed configuration diagram of the RF signal receiving apparatus 200 of FIG. 1, which may also calculate the distance to the RF signal generating apparatus 100 by simply receiving the continuous wave CW. After transmitting the response message in response to receiving the call message, the distance to the RF signal generator 100 may be calculated and output to the outside.

Referring to FIG. 3, first, the call message demodulator 230 includes an amplifier 232 and a demodulator 234 to amplify and demodulate the call message received through the omni-directional antenna 210 to perform a second microprocessor ( 280).

The response message modulator 240 also includes a modulator 244 and an amplifier 22 to modulate and level amplify the response message input from the second microprocessor 280 to the outside through the omnidirectional antenna 210. Send it out. The second switching unit 220 switches according to the switch control signal output from the second microprocessor 280 to operate the omnidirectional antenna 210 as one of the modulator 240 and the demodulator 230. It plays the role of connecting to.

Meanwhile, the two directional antennas 250 and 260 rotate together with each other by the rotation shaft. The directional antennas 250 and 260 are rotated by the second microprocessor 280 and, if the system is mounted on the robot, can be implemented by the rotation of the robot. In addition, the distance 2R between the two directional antennas 250 and 260 (where R is the distance between one antenna in the rotation axis between the two antennas rotating in conjunction) preferably has a value smaller than the CW wavelength λ. The reason for this is to calculate the distance L1 due to the phase difference, which will be described later.

Meanwhile, the amplifiers 272 and 274 amplify and output the continuous waves CW received through the directional antennas 250 and 260, respectively, and the phase and power detector 276 are the continuous waves input through the respective amplifiers 272 and 274. The received power of CW and the phase difference between two continuous waves CW are detected to output phase detection data and power detection data in the form of voltage.

The second microprocessor 280 controls the overall operation of the RF signal receiving apparatus 200. For example, when a call message is received through the call message demodulator 230, a response message is generated and outputted, and a switch control signal is output. The antenna is fixed to a direction in which the receiving power of the continuous wave is maximum, and then the direction is fixed. Calculate the distance (L1) by the phase difference between each of the detected continuous waves (CW), and the rotation angle (α) of the antenna rotated until the phase difference becomes zero in the antenna direction along with the distance (L1). Substituting Equation 4 to be described later, the distance to the RF signal generator 100 is calculated and output. In addition, when the second microprocessor 280 calculates and outputs the distance to the RF signal generator 100, the second microprocessor 280 may output a message requesting the oscillation stop of the continuous wave.

Hereinafter, an operation of the location tracking system according to an exemplary embodiment of the present invention will be described with reference to the operations of the microprocessors 140 and 280 provided in the RF signal generator 100 and the RF signal receiver 200, respectively.

4 is a flowchart illustrating an operation of the microprocessor 140 of FIG. 2, and FIG. 5 is a flowchart illustrating an operation of the second microprocessor 280 of FIG. 3. 6 illustrates the relationship between the received power of the continuous wave CW and the power detection data, and FIG. 7 illustrates the relationship between the phase difference and the phase detection data between the received continuous waves CW. 8 is a view for explaining a distance calculation process to the RF signal generator 100 according to an embodiment of the present invention.

Referring to FIG. 4, first, the first microprocessor 140 proceeds to step 310 when an outgoing command, ie, a command for calling the RF signal receiving apparatus 200, is received through the user I / F unit 170 in step 300. Proceed to output the call message for the call to the slave RF signal receiving apparatus 200 to the modulator 154. In this case, the first switching unit 120 is connected to the omnidirectional antenna 110 and the amplifier 160 by a switch control signal output from the first microprocessor 140. Therefore, the call message is wirelessly transmitted from the RF signal generator 100.

The second micro processor 140 transmitting the call message as described above controls the first switching unit 120 to connect the omni directional antenna 110 and the response message demodulator 130 to proceed to step 320. Checks if a is received. If the test result does not receive a response message, the slave call message is continuously transmitted within the prescribed number of transmission ranges (step 330) for a predetermined time. If no response message is received until the number of transmissions is exceeded, that is, a prescribed time is exceeded, the user I / F unit 170 notifies an error state to the alarm sound (step 340). However, if a response message is received in step 320, the first microprocessor 140 proceeds to step 350 and controls the continuous wave generator 152 to perform continuous wave transmission. In this case too, it is obvious that the switch must be switched so that the CW can be transmitted wirelessly through the omni-directional antenna 110.

As described above, after transmitting the CW, the first microprocessor 140 proceeds to step 360 to check whether the call stop request message is received, and when the call stop request message is received, to generate the RF signal. Stop it.

That is, the RF signal generator 100 according to the embodiment of the present invention modulates a call message and transmits it wirelessly under the control of the first microprocessor 140, and the continuous wave oscillated by the oscillator when the response message is received accordingly. RF transmission is performed by amplifying CW at a predetermined level.

Hereinafter, the operation of the RF signal receiving apparatus 200 will be described with reference to FIG. 5. First, in operation 400, the second microprocessor 280 checks whether a call message is received. For this inspection, the second switching unit 220 is controlled to connect the omnidirectional antenna 210 and the call message demodulator 230. If the call message is received, after switching the path of the second switching unit 220, the second microprocessor 280 proceeds to step 410 and outputs the response message to the response message modulator 240. Therefore, the modulated and amplified response message may be transmitted to the above-described RF signal generator 100 through the omnidirectional antenna 210.

Meanwhile, the second microprocessor 280 that controls the transmission of the response message switches the path of the second switching unit 220 again, and proceeds to step 420 to detect the transmission direction of the continuous wave CW. As a method of detecting the transmission direction of the continuous wave CW, the continuous wave CW may be generated when the reception power of the continuous wave CW is received through the two directional antennas 250 and 260 rotating in conjunction with each other. You can set it in the outgoing direction.

That is, the second microprocessor 280 may fix the directional antennas 250 and 260 at the point where the power detection data having the maximum value is input while monitoring the power detection data output from the phase and the power detector 276. For reference, the power detection data has a voltage type value as shown in FIG. 6, and the power detection data is proportional to the received power dB of the continuous wave CW. When the transmission direction of the continuous wave CW is detected in step 420, the second microprocessor 260 locates the directional antennas 250 and 260 at the detected position, and proceeds to step 430 to receive the signals through the directional antennas 250 and 260. Phase difference between CWs ) Is detected and the distance L1 based on the phase difference is calculated. In more detail,

First, since the second microprocessor 280 receives phase detection data of the continuous wave CW received from each of the directional antennas 250 and 260 through the phase and power detector 276, the second micro processor 280 is received through each of the directional antennas 250 and 260. Phase difference between CW ) Can be detected from the table of the graph shown in FIG. Referring to FIG. 7, if the phase detection data difference between the continuous wave CWs detected through the phase and power detector 276 is 900 mV, for example, the phase difference ( ) Is ± 90 ° as can be seen in FIG. 7. If the frequency of the transmitted continuous wave (CW) is used as 300 MHz, the wavelength of the continuous wave (CW) ( ) Value is 1m, it can be seen that L1 shown in Figure 8 is 25cm when substituted into the following equation (3) to obtain the distance L1 by the phase difference.

As described above, when the phase difference detection and the distance L1 based on the phase difference are calculated in step 430, the second microprocessor 280 proceeds to step 440 to calculate the antenna rotation angle α. The method for calculating the antenna rotation angle α can be obtained by rotating the directional antennas 250 and 260 until the phase difference becomes zero at the position where the reception power is maximum, and checking the rotation angle until then. That is, the rotation angle α of the antenna may be calculated by rotating the directional antennas 250 and 260 shown in FIG. 8 in a counterclockwise direction until the phase difference becomes zero. After calculating the distance L1 based on the antenna rotation angle α and the phase difference, the second microprocessor 280 proceeds to step 450 and the distance from the target to the first omnidirectional antenna 250 + L1 is equal to the second at the target. The distance D to the target, that is, the RF signal generator 100 can be obtained from the equation that the distance to the directional antenna 260 is the same. If this is expressed by an equation, it may be expressed by Equation 4 below.

R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction.

When the distance D to the RF signal generator 100 is calculated based on Equation 4, the second microprocessor 280 outputs it to a display device (not shown) or the controller of the robot system through an interface device. By transmitting to the RF signal generator 100 can be used for tracking. In operation 460, the second microprocessor 280 controls to transmit the message requesting the stop of the continuous wave CW so that the RF signal generator 100 receives it to stop transmission of the continuous wave CW. do.

As described above, the RF signal receiving apparatus 200 according to the embodiment of the present invention has the directivity in the direction in which the reception power of the continuous wave CW is received through the two directional antennas 250 and 260 rotating in conjunction with each other. The phase difference between the continuous waves CW received through each antenna is detected to calculate the distance L1 due to the phase difference, and the rotation angle α of the antenna rotated until the phase difference becomes zero in the antenna direction is determined. By calculating and outputting the distance to the RF signal generator 100 by substituting the equation (4) together with the distance (L1), the tracker or the called party can use this to track the position of the target.

As described above, since the present invention can calculate the distance to the source as well as the direction of the RF signal generator, there is an effect of accurately tracking the position of the transmitter, and using the calculated distance to the RF signal generator There is an advantage that can quickly and accurately track the originating device.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (10)

In the location tracking system, An RF signal generator for amplifying a continuous wave (CW) oscillated by an oscillator to a predetermined level and transmitting the RF; The distance by the phase difference is detected by detecting the phase difference between the continuous wave CW received through each of the directional antennas in the direction in which the reception power of the continuous wave CW received through the two directional antennas rotating in conjunction is maximum. (L1) is calculated and the distance to the RF signal generator by substituting the rotation angle α of the antenna rotated until the phase difference becomes zero in the antenna direction together with the distance L1 in Equation 5 below. RF signal receiving apparatus for outputting a; location tracking system comprising a. R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction. The method according to claim 1, wherein the RF signal receiving apparatus; Two directional antennas rotating in association with each other; Amplifiers for amplifying a continuous wave (CW) received through each of the antennas; A power and phase difference detector for detecting a received power of the continuous wave CW and a phase difference between the two continuous waves CW input through respective amplifiers; After fixing the antenna in the direction of the maximum reception power of the continuous wave CW, the distance L1 due to the received phase difference of the continuous wave detected in the direction is calculated and rotated until the phase difference becomes zero in the antenna direction. And a microprocessor that calculates and outputs a distance to the RF signal generator by substituting the rotation angle α of the antenna together with the distance L1 into the equation. The position tracking system according to claim 1 or 2, wherein the distance between the two rotating antennas is smaller than the wavelength lambda of the continuous wave CW. In the location tracking system, An RF signal generator for modulating and transmitting a call message and transmitting the RF by amplifying a continuous wave (CW) generated by an oscillator to a predetermined level when receiving a response message; When the call message is received through the omni-directional antenna, the response message corresponding to the modulation is transmitted and wirelessly transmitted, and the directionality in the direction in which the reception power of the continuous wave (CW) received through the two or more directional antennas rotating in conjunction is maximum. The phase difference between the continuous waves CW received through each antenna is detected to calculate the distance L1 due to the phase difference, and the rotation angle α of the antenna rotated until the phase difference becomes zero in the antenna direction is determined. And a RF signal receiver for outputting a distance to the RF signal generator by substituting the following equation (6) together with the distance (L1). R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction. The apparatus of claim 4, wherein the RF signal generator; A user interface unit for inputting a call command of the RF signal receiving apparatus; A first microprocessor for controlling the operation of the RF signal generator in accordance with a user command; A signal generator for modulating and outputting a call message or oscillating a continuous wave under the control of the microprocessor; An amplifier for amplifying the output of the signal generator and outputting the signal to the omni directional antenna; A demodulator for demodulating a response message received through the omnidirectional antenna and outputting the demodulated message to the microprocessor; And a switching unit controlled by the microprocessor and connecting the directional antenna to any one of the amplifier and the demodulation unit. The method according to claim 5, wherein the RF signal receiving apparatus; A call message demodulator for demodulating a call message received through the omnidirectional antenna; A response message modulator for modulating an input response message and transmitting the modulated response message to the omni directional antenna; A second switching unit for connecting the omnidirectional antenna to one of the modulator and the demodulator according to an input switch control signal; Two directional antennas rotating in association with each other; Amplifiers for amplifying a continuous wave (CW) received through each of the directional antennas; A phase and power detector for detecting the received power of the continuous wave CW and the phase difference between the two continuous waves CW input through respective amplifiers; When receiving a call message, it generates and outputs a response message, outputs a switch control signal, and fixes the antenna in a direction in which the reception power of the continuous wave is maximum, and then the distance due to the phase difference between the detected continuous waves in the direction. (L1) is calculated and the distance to the RF signal generator is substituted by substituting the rotation angle α of the antenna rotated until the phase difference becomes zero in the antenna direction with the distance L1 in Equation 6 above. And a second microprocessor for calculating and outputting the position tracking system. The system of claim 5, wherein the first microprocessor outputs an alarm sound through the user interface unit when a response message is not received for a predetermined time after the call message is transmitted. The position tracking system according to claim 6, wherein the second microprocessor outputs a transmission stop request message of a continuous wave (CW) after calculating a distance to the RF signal generator. A location tracking method of a system for tracking a location of a target that emits a continuous wave (CW), Detecting a direction in which the reception power of the continuous wave CW received through two directional antennas rotating in association with each other is maximum; Calculating a distance L1 due to a phase difference between the continuous waves CW received through each of the antennas in the direction of maximum reception power; Detecting a rotation angle (α) of the antenna rotated until the phase difference becomes zero in the direction of the maximum reception power; Calculating the distance (D) to the continuous wave (CW) transmission target by substituting the distance L1 and the antenna rotation angle? According to the phase difference into Equation 7 below; And outputting the calculated distance (D) to a display device or to an external device. R: The distance between one antenna in the axis of rotation between two antennas rotating in conjunction. 10. The method of claim 9, further comprising outputting a message requesting the stop of the continuous wave (CW) transmission to the target.