KR101873797B1

KR101873797B1 - A method for target location using the tdoa information matching

Info

Publication number: KR101873797B1
Application number: KR1020160025800A
Authority: KR
Inventors: 김산해; 송규하; 김소연; 곽현규; 장충수
Original assignee: 국방과학연구소
Priority date: 2016-03-03
Filing date: 2016-03-03
Publication date: 2018-07-03
Also published as: KR20170103260A

Abstract

In the present invention, when a plurality of spaced receivers perform position detection using Time Difference Of Arrival (TDOA) information generated when receiving a target signal, the virtual position of the target is gridded And a TDOA information sequence corresponding to each point is previously constructed as a matching table to compare the TDOA information sequence of the actually received signal with the TDOA information sequence. The position detection method according to the present invention includes the steps of collecting position information from a plurality of receivers disposed at a spaced position, generating a virtual position of the target, and generating a virtual TDOA information sequence corresponding to the generated virtual position Extracting an actual TDOA information sequence using the TOA information generated by the plurality of receivers based on a signal emitted from the target, Comparing the virtual TDOA information sequence included in the matching table to search for an information sequence index having a smallest difference between the extracted actual TDOA information sequence and the virtual TDOA information sequence as a result of comparison, Extracting the position as the virtual position information of the target, adding the precise position of the target using the extracted virtual position information, Step and a step of resetting the virtual position in the search area matching table generated the group using the precise location of the estimated

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detection method using time-

The present invention relates to a method for detecting a position of a target using time difference of arrival (TDOA) that occurs when a target signal is received by a plurality of receivers spaced apart from each other.

The technology for detecting the position of a threat (or target) is a representative technology of electronic warfare (EW), and the technology for such electronic warfare is required to have a high computation speed and high accuracy performance as technology develops .

In particular, a precise location detection technique using TDOA (Time Difference of Arrival) information, which is the arrival time difference of a signal generated when a threat signal is received by a plurality of receivers spaced apart from each other, In addition to the field, it is used as a basic position detection technology of passive radar in many advanced countries.

On the other hand, the conventional TDOA-based precision position detection technique requires an iterative calculation for solving a nonlinear equation and requires a high computational complexity. In order to solve the nonlinear equations, Detection performance is greatly influenced. Therefore, there is a need for a position detection method with fast computation speed and constant position detection performance as an initial value selection algorithm for precision position detection based on TDOA.

In order to overcome this problem, a technique of roughly detecting the position of the target by triangulation using the target direction information (AOA) and using it as an initial value has been researched / developed. To perform trigonometry, direction information should be derived from each receiver. Representative techniques include an amplitude comparison method for extracting direction information by comparing amplitudes of received signals, a phase comparison method using phase difference of received signals, and a method of deriving direction information using TDOA information. Among them, the amplitude comparison method has a disadvantage in that the direction detection accuracy is greatly deteriorated due to the amplitude mismatch between receiving channels. The phase comparison method is relatively accurate compared with the amplitude comparison method, but a plurality of isotropic antenna arrays must be used for precise measurement. Further, in order to accurately measure the phase difference between the two signals in the phase comparison method, other additional equipment is required, and the calculation complexity increases. In recent years, the development of multi-directional direction detection technology that combines amplitude comparison method and phase comparison method has been actively developed. However, due to structural constraints of hardware, direction detection accuracy is still not satisfactory, The variation is very large. On the other hand, the method of deriving the direction information using the TDOA information has a relatively high performance, but the performance is greatly degraded as the position of the target is closer to the receiver due to the assumption that the distance to the target should be sufficiently away from the receiver. If there is an information derivation error, as the direction of the target becomes closer to the reference line of the two receivers, the direction detection performance is degraded, and when the triangulation method is used, a shadow area or shading direction in which the position detection performance is greatly degraded is generated .

On the other hand, a technique has been developed in which initial values for solving nonlinear equations are set to a multiple value at a predetermined interval or randomly for a region of interest, and the result is not deviated to a local minimum value. As a result, There is a disadvantage in that the computation speed is lowered because it is necessary to perform an iterative calculation for accurate position detection with a large number of initial values.

The present invention is to provide a position detection method having a fast computation speed and a constant performance by using TDOA information and a pre-generated matching table in a plurality of receiver-based position detection systems spaced from each other.

The position detection method according to the present invention includes the steps of collecting position information from a plurality of receivers disposed at a spaced position, generating a virtual position of the target, and generating a virtual TDOA information sequence corresponding to the generated virtual position Extracting an actual TDOA information sequence using the TOA information generated by the plurality of receivers based on a signal emitted from the target, Comparing the virtual TDOA information sequence included in the matching table to search for an information sequence index having a smallest difference between the extracted actual TDOA information sequence and the virtual TDOA information sequence as a result of comparison, Extracting the position as the virtual position information of the target, adding the precise position of the target using the extracted virtual position information, Step and a step of resetting the virtual position in the search area matching table generated the group using the precise location of the estimation.

In the embodiment, in the step of generating the matching table, the virtual position of the target is generated in a lattice form of an interval defined by the user according to the operating environment and required performance of the system for estimating the precise position of the target, Create a table.

In an embodiment, the specific distance for setting the virtual location search interval may be determined based on a reliability level of the virtual location information of the target used to estimate the accurate location of the target, a time synchronization of the system for estimating the accurate location of the target The performance environment, the operating environment of the system for estimating the precise position of the target, and the mobile environment of the target.

In an embodiment, the resetting of the search interval in the matching table uses the virtual position information of the target used to estimate the estimated precision position and the precision position of the target.

In the embodiment, in the step of resetting the search interval in the matching table, when estimating the accurate position of the target using the plurality of virtual position information, a plurality of search intervals corresponding to the plurality of virtual position information are set do.

According to the present invention configured as described above, the position of the target is detected only through comparison between the virtual TDOA information sequence in the matching table once set before the receiver arrangement and the actual TDOA information sequence of the signal arriving at the plurality of spaced receivers during system operation .

According to the present invention, it is possible to adjust the degree of grating granularity at the time of generating the matching table by parameters alone, and to trade-off the position detection accuracy and the execution speed according to the system operating environment, Value, it is possible to derive the coarse position detection result at a fast execution speed by reducing the degree of gridding refinement.

Meanwhile, according to the present invention, since the matching table can be generated as a look-up table (LUT) when the arrangement of the receiver is determined, the matching table can be applied irrespective of the arrangement of receivers or the number of receivers. The matching table is generated in advance so that no additional operation is required in the position detection step in which the system is actually operated.

1 is a block diagram for explaining a position detection system according to the present invention.
FIG. 2 is a conceptual view illustrating a relationship between a target and a plurality of spaced-apart receivers according to a TDOA information-based position detection method.
3 is a flowchart illustrating a method of detecting a location using TDOA information matching according to the present invention.
4 is a conceptual diagram for explaining a configuration of a matching table having a virtual position of a target and a corresponding virtual TDOA information sequence.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a position detection system and method according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram for explaining a position detection system according to the present invention. FIG. 2 is a conceptual diagram illustrating a relationship between a target and a plurality of spaced apart receivers, for explaining a TDOA information-based position detection method. FIG. 3 is a flowchart for explaining a location detection method using TDOA information matching according to the present invention. FIG. 4 is a conceptual diagram illustrating a configuration of a matching table having a virtual location of a target and a corresponding virtual TDOA information sequence.

The position detection system 1000 using time difference information matching according to the present invention is configured to include a plurality of receivers 1 and a control unit 2 as shown in Figs. Here, a plurality of receivers (1, first receiver, second receiver, third receiver, etc.) are randomly distributed and arranged to be spaced apart from each other, as shown in Fig.

In the present invention, the control unit (2) receives position information from each of a plurality of receivers (1). That is, in the control unit 2, the respective positional information received from the receiver 1 is collected.

The control unit 2 has information on the virtual position of the target before each positional information is received from the receiver 1. [ The control unit 2 calculates and generates a virtual TDOA information sequence at each virtual point by gridding the virtual positions of the target 3 at regular intervals to generate a virtual TDOA information sequence corresponding to the virtual position . &Lt; / RTI >

Here, the matching table is generated by calculating the virtual TDOA information sequence corresponding to each virtual point by gridding the virtual position of the target. When the matching table is generated, the more accurate the virtual location of the target is, the higher the accuracy of the location detection can be obtained. As the granularization is finely detailed, the search time required for comparison with the virtual TDOA information sequence increases. However, since the search range of the matching table is set to only a part of highly reliable area using the previous position information after receiving the first signal, The time required can be greatly reduced.

The control unit 2 calculates a TOA (Time of Arrival) (arrival time) that is the time at which the actual target signal 4 is received based on the reception of the target signal 4 from the target 3 to the receiver 2 30) from the receiver (2).

Here, the information transmitted from the plurality of receivers 1 to the control unit 2 includes the position information 10 of the receiver 1, the TOA information 30 of the signal 4 received from the target 3, .

The control unit 2 then extracts the actual TDOA information sequence from the TOA (Time of Arrival) that the actual target signal 4 received (or collected) from the receiver 2 is received.

The control unit 2 determines whether the received information is information on the first received signal received from the target 3. If it is determined that the received signal is the first received signal, And searches the information column index having the smallest difference between the actual TDOA information column extracted from the received signal and the entire virtual TDOA information column included in the configured matching table.

Then, the control unit 2 extracts the virtual position corresponding to the searched index as positional information, and stores the extracted positional information. The stored location information 50 is utilized to extract location information on the first and subsequent received signals. On the other hand, when it is determined that the received signal is the first and subsequent received signals, the control unit 2 sets only a valid reliable partial section among the entire matching tables using the previously stored location information 50 do. That is, the control unit 2 searches for the information column index having the smallest difference among the actual TDOA information sequence extracted from the currently received signal and the virtual TDOA information sequence within a partial section set in the matching table. Then, the control unit 2 extracts the virtual position corresponding to the searched index as positional information, and stores the extracted positional information in the system. On the other hand, this process can be repeatedly performed whenever the signal 4 from the target 3 is received by the plurality of spaced-apart receivers 1 and the TOA information 20 is received from the receiver 1 .

The position detection system according to the present invention as described above can be used to finally acquire the position of the target through the initialization step 20, the position detection step 40 and the precise position detection step 60, as shown in FIG. do.

First, in the initialization step 20, as shown in FIG. 3, a step of collecting position information 10 of a plurality of spaced-apart receivers 1 received from a receiver 1 in a control unit 2 21). Then, the control unit 2 generates a target virtual location 100 by gridding at a specific interval as shown in FIG. 4, calculates a virtual TDOA information sequence 101 at each virtual point, And a step (22) of constructing a matching table having a position and a corresponding virtual TDOA information sequence. The virtual TDOA information column 101 can be calculated as a point 101 of the virtual position of the target and the position information 10 of the collected receiver as shown in Equation 1 below.

here

Transmits the signal at the virtual position of the j-th target and transmits the signal at the i-th receiver position

And the first receiver position

Where N is the total number of receivers, M is the total number of virtual positions of the target generated by grating, and c is the speed of light.

Represents the jth virtual position among the virtual positions of the target generated by grating.

As described above, a matching table can be generated as shown in Table 1 below by calculating the virtual TDOA information sequence in all the virtual locations 100 of the target.

In this case, when the matching table is generated, the degree of granularization can be adjusted only by parameters, so that the position detection accuracy and the execution speed can be traded off according to the system operating environment. Therefore, It is possible to derive the coarse position detection result at a high speed by decreasing the degree of granularization.

Upon completion of the initialization step 20, the position detection step 40, which detects the position of the real target 3, enters.

First, a plurality of spaced-apart receivers 1 transmit TOA information 30 of signal 4 emitted at target 3 to controller 2. [ The control unit 2 collects all the TOA information 30 received from the receiver 1 and performs a step 41 of extracting an actual TDOA information sequence on the basis of a specific receiver. In this step, the control unit 2 can directly transmit the TOA information 30 from the plurality of receivers 1 and extract the TDOA information using the difference. The receiver 1 transmits raw data such as IQ data of the received signal to the control unit 2 when the receiver 1 can not derive the TOA information 30 from the receiver 1 itself. Then, the control unit 2 can directly estimate the TDOA through a specific algorithm. The extracted actual TDOA information sequence can be expressed as Equation 2 below.

Thereafter, the control unit 2 performs a step 42 of determining whether or not the actual TDOA information sequence extracted in the step 41 is based on the first received signal information.

Here, if it is determined by the first received signal information, the control unit 2 compares the extracted actual TDOA information sequence with all the virtual TDOA information sequences stored in the matching table as shown in Equation 3 below, A step 43 of searching for an index k of the virtual position is performed.

The above equation is used to explain the concept of finding the index having the smallest difference by comparing the actual TDOA information sequence with the virtual TDOA information sequence, and it is possible to apply another comparison search algorithm to increase the search speed.

Thereafter, the control unit 2 performs step 44 of extracting a virtual position corresponding to the index among all the virtual positions 100 of the target as shown in the following Equation 4, and stores the position value as the current position information Step 47 is performed.

On the other hand, if it is determined in step 42 that the extracted actual TDOA information sequence is based on the first received signal information, the controller 2 determines that the extracted TDOA information sequence is based on the signal information received after the first time, A step 45 of setting a virtual position existing within a specific distance d based on the previous position information 50 among the entire virtual positions 100 as a search interval 102 is performed. The previous location information 50 used herein may be used through one or more and a combination of the location of the estimated location in the location detection step 40 or the location of the estimated location in the precise location detection step 60 to be described hereinafter And can also be determined by a combination of multiple previous location results. Here, the specific distance d for setting the virtual location search interval can be set in a parameter form according to the reliability of the used location information 50, the time synchronization performance of the system, the operating environment of the system, the moving environment of the target, It is possible to set an effective section having high reliability among the entire search intervals. In case of using a plurality of pieces of position information 50, it is possible to set a plurality of search intervals. In this case, only the overlapping virtual positions are searched for. FIG. 3 shows an example of a search interval setting when two pieces of position information 50 are used. Through this process, the number of virtual TDOA information columns for comparison search is M

.

Then, the control unit 2 compares the extracted actual TDOA information sequence with the L sets of the virtual TDOA information sequences stored in the matching table, and finds the index k of the virtual position with the smallest difference Performing step (46), performing a step (44) of extracting a virtual position corresponding to the index k from the virtual position (102) in the set interval, and storing the position value as current position information (47) .

Then, when the control unit 2 finishes the position detection step 40, the position of the target estimated in the position detection step 40

(Step 60).

Performing precise position detection (61) may include detecting the position of the target estimated in the position detection step (40)

Is used as an initial value of the solution of the nonlinear equation to perform more accurate iterations to estimate the position of the target more precisely, and the precise position information storage and display step 62 is performed at the precise position of the estimated target.

The position detection step 40 and the precise position detection step 60 according to the present invention are performed such that the target signal 4 is received by the plurality of spaced receivers 1 after the initialization step 20 and the TOA information 30 May be repeatedly performed in real time or by a specified period or the like.

In addition, each sub-step has a characteristic that the order can be changed or can be performed simultaneously depending on the reception of necessary information and the order of delivery.

Claims

Collecting respective position information from a plurality of receivers disposed in a spaced apart position;
Generating a virtual location of the target and generating a matching table composed of a virtual TDOA information sequence corresponding to the generated virtual location;
Extracting an actual TDOA information sequence using TOA information generated in the plurality of receivers based on a signal emitted from the target;
Comparing the extracted actual TDOA information sequence with a virtual TDOA information sequence included in the matching table and searching for an information sequence index having a smallest difference between the extracted actual TDOA information sequence and the virtual TDOA information sequence ;
Extracting a virtual position corresponding to the searched information column index as the target virtual position information;
Estimating a precise position of the target using the extracted virtual position information; And
And resetting the virtual location search section in the pre-generated matching table using the estimated precise location,
Wherein the specific distance for setting the virtual location search interval includes at least one of a degree of reliability of the target virtual location information used to estimate the precise location of the target, a time synchronization performance of the system for estimating the precise location of the target, Wherein the target position is set in a parameter form based on at least one of an operating environment of the system for estimating the precise position and a moving environment of the target.

2. The method of claim 1, wherein, in the step of generating the matching table,
And a matching table is generated by generating a virtual position of the target in a grid form of a gap defined by a user according to an operating environment and required performance of the system for estimating the precise position of the target,

delete

2. The method of claim 1, wherein the resetting of the search interval in the matching table utilizes the estimated precision position and the virtual position information of the target used to estimate the precision position of the target.

2. The method of claim 1, wherein, in the step of resetting the search interval in the matching table, when estimating the precise position of the target using the plurality of virtual position information, a plurality of search intervals corresponding to the plurality of virtual position information The position detection method comprising: