KR20010111982A - Method and apparatus for tracking position - Google Patents

Abstract

In the location tracking method according to the present invention, when the location tracking terminal can receive radio waves from the base station, a plurality of base stations communicate with the location tracking terminal to calculate the propagation delay value between the base station and the location tracking terminal, The base station transmits the calculated propagation delay value to the location information providing means, calculates the location of the location tracking terminal using the transmitted propagation delay value in the location information providing means, and positions the calculated location information through the base station. By transmitting to the tracking terminal, the location tracking terminal tracks the current position, and continuously updates and stores the tracked current position in the memory.

Here, when the location tracking terminal is unable to receive radio waves from the base station, by using the inertial navigation device provided in the location tracking terminal based on the current position of the most recent location tracking terminal updated and stored in the memory The location of the location tracking terminal is characterized by tracking the location.

This invention has the advantage of being able to track the location continuously when it is possible to receive radio waves from the base station as well as when it is impossible to receive radio waves.

Description

Position tracking method and location tracking terminal {Method and apparatus for tracking position}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a location tracking system, and more particularly, to a location tracking system capable of receiving a base station radio wave to track a location and continuously tracking a location even when the base station radio wave cannot be received.

In general, the position tracking system is a GPS (Global Positioning System), which means that four or five satellites are placed on each of the orbits on six orbits that are inclined at 55 degrees with the earth's equator. It allows you to communicate with more than one satellite and receives a signal containing a specific code (C / A code, Coase / Acquision code) from GPS satellites to determine your current position (longitude, latitude, altitude) at some point in time. It is a system that can calculate.

The method of measuring a location using GPS, by analyzing a specific code of a signal from a GPS satellite to find out when the signal was sent, the time it takes for the signal of the satellite to leave the satellite to the receiver By calculating, the position is measured. That is, since the speed of the satellite signal (usually the speed of light) is known by using a wireless positioning method that tracks the position by multiplying the speed of the radio wave by the speed to obtain the moving distance, the speed of the satellite signal and the time of arrival are used. To get the distance from the satellite to the receiver. And, to know the actual location, we need to know three coordinates of latitude, longitude, and altitude, and four unknowns of clock error. Since the GPS receiver always receives signals from four or more satellites, we obtain four unknown coordinates as four observations. You can track the location of.

On the other hand, instead of receiving a radio wave from the satellite to track the location as a method of tracking the location, there is a network based location system that receives the signal of the base station to track its location, the network based location system currently In a cellular system that implements a mobile phone, a system that tracks the location of a mobile station relative to the base stations by measuring the distance between the mobile station and four or more base stations whose location is known, and displays the location of the mobile station relative to the base stations. to be.

Here, with reference to the accompanying drawings will be briefly described a conventional network based location system.

1 is a diagram illustrating a conventional network based location system.

Referring to FIG. 1, a conventional network based location system includes a mobile station 101, a plurality of base stations 102 for communicating with the mobile station 101 to measure a propagation delay, and a propagation delay of the base station 102. And a location server 103 for calculating the location of the mobile station 101 using the value and providing the location information to the mobile station.

First, the mobile station 101 continuously acquires pilot signals of neighboring base stations 102 even in a reception standby state, synchronizes with the base stations 102, and makes a call channel and communication for communication such as a telephone call and data transmission. Perform the task of assigning a channel.

At this time, the mobile station 101 returns the pilot signal received from the base station 102 to the base station 102 as it is, and propagates the propagation delay of the pilot signal from the base station, that is, the mobile station 101 to the base station 102. Allows you to measure the time it reaches.

The base station 102 transmits the calculated propagation delay data to the location server 103, and the location server 103 calculates a distance between the base station 103 and the mobile station 101, and calculates the calculated propagation delay data. By transmitting the location information to the mobile station 101 through the base station 102, the mobile station 101 can track its location.

In this case, in order to track the position, the mobile station 101 needs to know three coordinates of latitude, longitude, and altitude, and four unknowns of clock error. Therefore, the mobile station 101 receives radio delay data from four or more base stations and adjusts the position of the mobile station 101. Calculate

In this network based location system, the base station has information about its location, and calculates distance calculation, location tracking, map control, etc. and transmits it to the mobile station, so there is no additional hardware in the mobile station. It is possible to implement a service.

However, such a network based location system has a problem in that the location cannot be tracked when the radio wave cannot be received from the base station 102.

On the other hand, the position tracking method is an inertial navigation system (INS / DR sensor, Inertial Navigation System / Dead Reckoning sensor), which has three gyroscopes that detect angular displacement in different directions and acceleration in one direction. The two sensing sensors are combined to measure the attitude and acceleration change of a moving object in three dimensions so that it can track its relative position relative to its initial position.

That is, the inertial navigation apparatus tracks its position by measuring the orientation angle, which is its attitude for a relatively short time, and the acceleration, and calculating the relative position with respect to the initial position when the acceleration angle is moved from the orientation angle. Will be.

The inertial navigation system as described above has the advantage of always being able to track its own location without receiving a signal from a base station or a satellite. However, the initial position is important as it tracks the relative position to its initial location. In addition, the error is small for a short time, but the error accumulates for a long time has the disadvantage that the error of its own location information increases.

The present invention has been made in view of the above-described conditions, and includes an inertial navigation device in a mobile station and tracks the location using a network based location system, so that the location can be tracked even where radio waves of the base station cannot be received. The purpose of the present invention is to provide a location tracking method and a location tracking terminal capable of continuously accurate location tracking.

1 is a view showing a conventional network based location system.

2 is a view showing a location tracking system employed in the location tracking method according to the present invention.

3 is a view showing the internal configuration of the location tracking terminal according to the present invention.

Figure 4 is a view showing an embodiment of a location tracking terminal according to the present invention.

5 is a view showing an execution process of a location tracking method by the location tracking terminal of FIG.

<Explanation of symbols for the main parts of the drawings>

101, 201 ... mobile station 102, 202 ... base station

103, 203 ... location server 301, 401 ... memory

302a ... Gyroscope 302b ... Acceleration sensor

303 ... Analog / Digital Converter 304 ... DSP

305 ... Miccom 405c ... Multiplier

In order to achieve the above object, the location tracking method according to the present invention, when the location tracking terminal can receive radio waves from the base station, the communication between the location tracking terminal in the plurality of base stations between the base station and the location tracking terminal The propagation delay value is calculated, the base station transmits the calculated propagation delay value to the location information providing means, and the location information providing means calculates the position of the location tracking terminal using the transmitted propagation delay value. The location information is transmitted to the location tracking terminal through the base station, so that the location tracking terminal tracks the current location, and continuously updates and stores the tracked current location in the memory.

Here, when the location tracking terminal is unable to receive radio waves from the base station, by using the inertial navigation device provided in the location tracking terminal based on the current position of the most recent location tracking terminal updated and stored in the memory The location of the location tracking terminal is characterized by tracking the location.

In addition, the position tracking terminal according to the present invention, the inertial navigation device comprising a memory for storing its initial position information, a gyroscope for measuring its attitude and an acceleration sensor for measuring its acceleration, and An analog / digital converter for converting an analog signal output from a gyroscope and an acceleration sensor into a digital signal, a DSP for converting the digital signal into processable data, initial position information stored in the memory and inputted from the DSP Characterized in that it comprises a microcomputer to track its location using digital data.

According to the present invention as described above, the position can be continuously tracked when the radio wave can be received from the base station as well as when the radio wave cannot be received.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the location tracking method according to the present invention will be described in general, a base station dedicated mode in which the location tracking terminal can receive radio waves from the base station, and a dedicated mode of inertial navigation apparatus in which the location tracking terminal cannot receive radio waves from the base station. Two modes can be used to track the location of the location tracking device.

Here, when the location tracking terminal can receive a radio wave from the base station, a plurality of base stations communicate with the location tracking terminal to calculate the propagation delay value between the base station and the location tracking terminal. The base station transmits the calculated propagation delay value to the location information providing means, calculates the location of the location tracking terminal using the transmitted propagation delay value in the location information providing means, and calculates the calculated location information. It transmits to the location tracking terminal through the location tracking terminal to track the current location, and continuously update and store the tracked current location in the memory.

In addition, when the location tracking terminal is unable to receive radio waves from the base station, by using the inertial navigation device provided in the location tracking terminal based on the current position of the most recent location tracking terminal updated and stored in the memory Keep track of your location.

A location tracking system employed in the above location tracking method will be described in detail with reference to the accompanying drawings.

2 is a view showing a location tracking system employed in the location tracking method according to the present invention.

2, a position tracking system according to the present invention includes a mobile station (position tracking terminal) 201 including an inertial navigation device 201b for tracking its position and acceleration and tracking its position. Calculates the position of the mobile station 201 using the plurality of base stations 202 for measuring the propagation delay value with the mobile station 201 and the propagation delay values of the plurality of base stations 202. And a location server 203 as location information providing means for providing the calculated location information to the mobile station 201 to cause the mobile station 201 to track the location.

Referring to the operation of the location tracking system of the present invention having the configuration as described above are as follows.

First, if mobile station 201 can receive radio waves from base station 202, mobile station 201 receives pilot signals from base station 202 and echoes them, and base station 202 echoes from mobile station 201. The received pilot signal is calculated to calculate the time at which radio waves propagate between the mobile station 201 and the base station 202, that is, the propagation delay value. Then, when the calculated propagation delay value is transmitted to the location server 203, the location server 203 calculates the position of the mobile station 201 using the propagation delay value and the position information of the calculated mobile station 201. Is transmitted to the mobile station 201 through the base station 201.

The mobile station 201 then receives the location information and tracks its location.

At this time, since the mobile station 201 needs to know three coordinates of latitude, longitude, and altitude, and four unknowns of clock error in order to track the position, the mobile station 201 receives the radio wave delay data from four or more base stations to determine the position of the mobile station 201. Calculate

When the mobile station 201 receives the radio wave from the base station 202 and tracks its location, the mobile station 201 continuously updates its current location information in the memory 201a.

At this time, when the mobile station 201 cannot receive radio waves from the base station 202, the last position information of the updated position information is set to its initial position and the inertial navigation is performed based on the initial position. By using the device 201b, the position and acceleration of the mobile station 201 are measured to calculate a relative position with respect to the initial position to continuously track its position.

When the mobile station 201 can receive radio waves from the base station 202 again, the mobile station 201 receives location information from the location server 203 through the base station 202 to track its own location.

Accordingly, such a location tracking system can receive a radio wave from the base station 202 to track its location, while continuously tracking the location even where the radio wave of the base station 202 cannot be received.

On the other hand, the mobile station consists of a terminal that can receive its radio wave from the base station to track its position, and at the same time can track its position using the inertial navigation apparatus provided even when it is unable to receive the radio wave from the base station. It will be described in detail with reference to the accompanying drawings.

3 is a view illustrating an internal configuration of a location tracking terminal according to the present invention, the location tracking terminal according to the present invention includes a memory 301 for storing its initial location information, and a gyroscope 302a for measuring its posture. And an inertial navigation device 302 including an acceleration sensor 302b for measuring its own acceleration, and an analog signal output from the gyroscope 302a and the acceleration sensor 302b for converting it into a digital signal. An analog / digital converter 303, a DSP 304 for converting the digital signal into processable data, and its own position using the initial position information and digital data input from the DSP 304 The microcomputer 305 is included.

Referring to the operation of the location tracking terminal as described above, first, the microcomputer 305 tracks its location using initial location information stored in the memory and digital data input from the DSP 304, As described above, if the location tracking terminal 201 can receive the base station signal, the location tracking terminal 201 receives the radio wave from the base station to track its own location. That is, when the base station 201 calculates a propagation delay value between the location tracking terminal 201 and the base station 202 and transmits the calculated propagation delay value to the location server 203, the location server 203 is The location of the location tracking terminal 201 is calculated using the propagation delay value, the location information of the location tracking terminal 201 is transmitted to the location tracking terminal 201 through the base station 201, and the location tracking terminal 201 Receives the location information to track their location.

The microcomputer 305 continuously updates and stores its current location, which has been received and tracked by the base station 202, in the memory 301.

Then, the gyroscope 302a and the acceleration sensor 302b of the inertial navigation device 302 output a signal having information related to its attitude and acceleration, and the output analog signal is transmitted to the analog / digital converter 303. The digital signal is converted into digital data which can be processed by the microcomputer 305 by the DSP 304 and input to the microcomputer 305.

At this time, when the location tracking terminal 201 is unable to receive radio waves from the base station 202, the microcomputer 305 receives the posture and acceleration information of the digital data input from the DSP (304) By using the current position stored in the memory 301, the current position immediately before the radio wave is cut off from the base station 202 is used as the initial position to track its own position.

Here, an embodiment of the location tracking terminal according to the present invention will be described.

4 is a view showing an embodiment of a location tracking terminal according to the present invention.

Referring to FIG. 4, the location tracking terminal according to the present invention includes an initialization information unit 401 storing initialization information of the terminal when the power is turned on, and a memory 402 in which error correction information and location information are updated and stored. And an inertial navigation device 403 including a gyroscope 403a for measuring its own posture and an acceleration sensor 403b for measuring its own acceleration, and an analog signal output from the inertial navigation device 403. Converts the signal into a digital signal and corrects the error, a DSP 405 for converting the signal output from the error compensation circuit 404 into processable digital data, and the memory ( The microcomputer 406 tracks its position using the position information stored in the 401 and the digital data input from the DSP 405, and gravity is applied to correct an error of the inertial navigation apparatus 403. Underground it is configured to include a gravity calculation unit 408 for transmitting to the secondary sensor 407 and the DSP (405) to calculate the gravity from the output of the secondary sensor 407.

Here, the DSP 405 is a magnetic world calculation unit 405a for calculating a posture using a digital signal input from the error compensation circuit 404 and a coordinate conversion unit 405b for converting coordinates, and the gravity calculator. A first integrator 405d that integrates a multiplier 405c for correcting the error of the coordinates converted by the coordinate transformation unit 40b based on the output value of 408 and an output signal of the multiplier, and calculates its own speed and moving distance ) And a second integrator 405e.

Referring to the method for tracking the location using the location tracking terminal of the present invention having the configuration as described above are as follows.

FIG. 5 is a view illustrating an execution process of a location tracking method by the location tracking terminal of FIG. 4. As shown in FIG. 4, when the terminal is powered on, the DSP 405 and the microcomputer 406 may initialize the initialization information unit 401. The initialization information is read from the setup information (step 501).

The microcomputer 406 communicates with the base station to track its position (step 502), and measures its posture and acceleration by the gyroscope 403a and the acceleration sensor 403b of the inertial navigation apparatus 403. When output, the error compensating circuit 404 converts the output analog signal into a digital signal, and corrects the error by using the error correction information stored in the memory 401 and transmits it to the DSP 405. Then, the DSP 405 converts the input digital signal into data that can be processed by the microcomputer 406 and transmits the digital signal to the microcomputer 406.

Here, since the inertial navigation apparatus 201b calculates a position relative to the initial position, the error is small for a short time, but as the time is longer, the error accumulates and the error of the position information becomes larger. Inertial navigation device that stores various information such as latitude, longitude, pseudorange, carrier phase information, etc. in the memory 401 and accumulates with time in the error compensation circuit 404 using the information stored in the memory 401 ( The error of 403 is corrected.

In addition, the present invention receives the radio wave from the base station 202, tracks its current position, updates and stores the current position in the memory 401, and inertial navigation apparatus using the updated current position as an initial position By using the 201b to keep track of its own position, the error of the position information calculated by the inertial navigation apparatus 201b can be minimized.

Among the digital signals output from the error compensating circuit 404, the signals output from the gyroscope 403a are processed by the magnetic field calculator 405a so that information about the posture is input to the microcomputer 406, and the digital signal. The signal output from the acceleration sensor 403b is input to the coordinate conversion unit 405b and converted into coordinates related to the map information, and the gravity calculation unit 408 uses the gravity measured by the auxiliary sensor 407. After calculating, correcting the error of the transformed coordinates in the multiplier (405c) using the calculated gravity value, the coordinate is corrected in the first integrator (405d) to calculate the speed, and the speed Integrate in the second integrator 405e to obtain the moving distance and transmit it to the microcomputer 406.

Here, since the acceleration sensor 403b varies according to the gravity value, the auxiliary sensor 407 measures gravity, calculates the measured gravity in the gravity calculator 408, and multiplies 405c. ) To correct the error of the acceleration sensor 403b.

On the other hand, the microcomputer 406 determines whether the sensors included in the terminal are normal using digital data input from the DSP 405 (step 503), and if the sensor is not normal, provides the inertial navigation apparatus service to the terminal. A message indicating that it is impossible can be displayed and the base station is switched to the dedicated mode (step 504).

In operation 505, it is determined whether there is a base station signal, and if there is no base station signal, a location tracking service cannot be provided, and thus a message indicating that a location tracking service cannot be provided to the terminal is displayed (step 506). As a result of the determination, if there is a base station signal, the base station communicates with the base station and tracks its location (step 502).

On the other hand, when the sensor is normal as a result of the determination in step 503, the microcomputer 406 tracks its position by using digital data input from the DSP 405, that is, information about posture, speed, and movement distance. Compare the location information with the location information tracked by communicating with the base station to correct the error of the location information tracked from the output signal of the inertial navigation device 403, and store the information in the memory, and communicate with the base station to track One location information is continuously updated and stored in the memory as its current location (step 506).

In this case, the error of the inertial navigation apparatus 403 is generally corrected because the position information tracked by communicating with the base station is more accurate than the position information tracked by the inertial navigation apparatus 403.

Then, the microcomputer 406 determines whether there is a base station signal (step 507). If there is a base station signal, the microcomputer 406 communicates with the base station to track the position, corrects an error of the inertial navigation apparatus 403, and corrects the current position of the terminal. If there is no base station signal as a result of the determination of step 507, the controller switches to the inertial navigation apparatus-only mode (step 508) and tracks its own position using only the inertial navigation apparatus (step 509). At this time, the inertial navigation device 403 keeps track of its position by using the current position information stored in the memory as the initial position immediately before the base station signal is cut off.

As described above, the location tracking system according to the present invention receives the radio wave from the base station and tracks its position, and at the same time keeps track of the position using the inertial navigation apparatus even when the radio wave cannot be received from the base station. The advantage is that you can track your location.

In addition, since the location information tracked by communicating with the base station is continuously updated and stored, and the stored location information is used as the initial location information, there is an advantage of minimizing the error of the inertial navigation apparatus.

Claims (3)

If the location tracking terminal can receive radio waves from the base station, the base station communicates with the location tracking terminal to calculate the propagation delay value between the base station and the location tracking terminal, The base station transmits the calculated propagation delay value to the location information providing means and calculates the location of the location tracking terminal using the transmitted propagation delay value in the location information providing means. And transmitting the calculated location information to a location tracking terminal through a base station so that the location tracking terminal tracks the current location and continuously updates and stores the current location in memory. The method of claim 1, When the location tracking terminal cannot receive radio waves from the base station, the location tracking terminal uses its inertial navigation device to update its location based on the current location of the most recent location tracking terminal. Position tracking method for tracking the position of the location tracking terminal by tracking. Memory that stores its initial location information, An inertial navigation device comprising a gyroscope measuring one's posture and an acceleration sensor measuring one's own acceleration, An analog / digital converter for converting an analog signal output from the gyroscope and the acceleration sensor into a digital signal; A DSP for converting the digital signal into processable data; And a microcomputer that tracks its own location using initial position information stored in the memory and digital data input from the DSP.