JPH05150038A - Track tracking processor - Google Patents

Abstract

PURPOSE:To provide a track tracking processor provided with the function of preventing the accuracy and stability degradation of a smoothed position and smoothed speed even in the case of the data rate of target data being high. CONSTITUTION:A time difference computing part 7 obtains the latest track time from a track correlative processing part 2, and computes the difference between the latest track time and the track time obtained the last time to obtain the latest radar search time interval. A motion judging part 8 judges the moving state of an aircraft, that is, whether to be constant velocity linear motion, turning motion (maneuvered state), or the like, on the basis of smoothed position data and smoothed speed data. A smoothing coefficient computing part 9 computes position-speed smoothing coefficients (alpha, beta) to be used this time on the basis of track distance R from a radar installed position inputted from the outside of this drawing, the above-mentioned detected time difference and the above-mentioned judged index. In other words, plural tables regarding the position-speed smoothing coefficients (alpha, beta) are provided in the content variable state. The smoothed position and speed can be thereby obtained stably with accuracy by the appropriate coefficients even in the case of the data rate of target data being high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track tracking processing device of a three-dimensional radar, and more particularly to a track suitable for an electronic scanning type three-dimensional radar in which the beam scanning period is changed according to the search area within the radar coverage area. The present invention relates to a tracking processing device.

[0002]

2. Description of the Related Art As is well known, a track tracking processing device of a three-dimensional radar is basically capable of correlating and tracking a track based on search data acquired by the radar and a tracking gate that is variably set. The smoothed position is calculated from the position of the track according to the smoothing coefficient of the position, and the smoothed velocity is calculated from the smoothed position according to the velocity smoothing factor.

Here, in the conventional three-dimensional radar, a method of beam scanning the coverage area at a constant cycle is adopted. Therefore,
The data rate of the target data obtained by the radar search is almost constant, but the radar search cycle is a cycle in which the target can be displaced sufficiently large for the measurement error of the radar, so the obtained data rate must be constant. Does not affect the calculation of the smoothing position and the smoothing speed. Therefore, in the track tracking processing device used in the conventional three-dimensional radar, the smoothed position and the smoothed speed are obtained by using the smoothing coefficient of the position and the speed which is simulated in advance and fixedly set in the table. ..

[0004]

In the electronic scanning type three-dimensional radar, the beam scanning cycle is appropriately changed according to the search area in the coverage area, that is, the search cycle is shortened in the area where the target exists. If a method of performing can be adopted, the tracking performance can be improved. However, shortening the search cycle means increasing the data rate, so
When using the conventional track tracking processing device, there are the following problems.

First, since the radar measurement error influences the calculation of the smoothed position and the smoothed velocity, the tracking performance can be improved for an aircraft making a turning flight, but for an aircraft making a constant-velocity linear flight. Has a problem that tracking becomes unstable.

Further, in the conventional track tracking processing apparatus, the same tracking processing is performed on all the aircraft regardless of the distance from the installation position of the radar to the position where the aircraft is present. When the data rate of the target data becomes high, the influence of the azimuth angle measurement error becomes noticeable especially for the aircraft at a long distance from the radar installation position, the smoothing speed is disturbed, and the accuracy of the smoothing position is reduced. There is also the problem of deterioration.

An object of the present invention is to provide a track tracking processing apparatus suitable for an electronic scanning type three-dimensional radar which adopts a method of appropriately changing the beam scanning period according to the search area in the coverage area.

[0008]

In order to achieve the above object, the track tracking processing device of the present invention has the following configuration. That is, the track tracking processing device of the present invention correlates the track based on the search data acquired by the three-dimensional radar and the tracking gate that is variably set, and calculates the smoothed position from the position of the track where the correlation is obtained. In a track tracking processing device, which performs a smoothing coefficient according to a smoothing position and calculates a smoothed speed from a smoothed position according to a speed smoothing coefficient; a means for calculating a time difference between a previous time and a current time of a correlated track; Means for determining the motion state of the aircraft based on the smoothed position and the smoothed velocity; and calculating a smoothing coefficient for the position and velocity based on the distance from the radar installation position of the aircraft, the time difference, and the motion state of the aircraft. And means for doing so.

[0009]

Next, the operation of the track tracking processing device of the present invention configured as described above will be described. In the present invention, the smoothing coefficient of the position and velocity is calculated based on the distance from the radar installation position of the aircraft, the detection time difference, and the motion state of the aircraft. Therefore, the present invention can be applied to an electronic scanning type three-dimensional radar in which the scanning cycle is shortened or changed according to the search area, and even if the data rate of the target data becomes high, an appropriate smoothing coefficient corresponding to the data rate can be used. It is possible to prevent the accuracy of the smoothing position and the smoothing speed from being deteriorated due to the increase, and it is possible to stabilize the tracking even for an aircraft flying in a straight line.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a track tracking processing device according to an embodiment of the present invention. 1, the track tracking processing device of the present invention includes a coordinate conversion processing unit 1, a track correlation processing unit 2, a position smoothing processing unit 3, a speed smoothing processing unit 4, a position prediction processing unit 5, and a tracking gate calculation processing unit. In addition to 6, a time difference calculation unit 7, a motion determination unit 8, and a smoothing coefficient calculation unit 9 are provided.

In FIG. 1, since the search data acquired by the three-dimensional radar is defined by the distance R and the angle θ, the coordinate conversion processing unit 1 defines it as data (X-Y orthogonal coordinate system data).
_n , Y _n ) and output to the track correlation processing unit 2.

The track correlation processing unit 2 performs correlation processing between the current position data input from the coordinate conversion processing unit 1 and the previous position data based on the tracking gate from the tracking gate calculation processing unit 6 to obtain correlation. The aircraft track data is provided to the position smoothing processing unit 3, and the correlated aircraft track time data is output to the time difference calculation unit 7.

The position smoothing processor 3 is a track correlation processor 2.
The target measurement position (X _n , Y _n ) of this time, the predicted position (X _pn , Y _pn ) from the predicted position processing unit 5, and the smoothing coefficient α of the position from the smoothing coefficient calculation unit 9 Is applied to the following equations 1 and 2 to calculate the target smoothing position (X _n bar, Y _n bar) at this time. This is given to the velocity smoothing processing unit 4 and the motion determination unit 8.

[0014]

[Equation 1]

[0015]

[Equation 2]

The velocity smoothing processing unit 4 receives the target smoothing position (X _n bar, Y _n bar) input from the position smoothing processing unit 3 and the prediction input from the position prediction processing unit 5. The position (X _pn , Y _pn ), the speed smoothing coefficient β from the smoothing coefficient calculating unit 9 and the radar search time interval ΔT _{n of} this time are applied to the following mathematical expressions 3 and 4 to smooth the target of this time. The conversion speed (X _n dot bar, Y _n dot bar) is calculated. This is given to the position prediction processing unit 5 and the motion determination unit 8. In Formulas 3 and 4, the X _n-1 dot bar and the Y _n-1 dot bar are the X component and Y component of the target smoothing speed calculated last time.

[0017]

[Equation 3]

[0018]

[Equation 4]

The position prediction processing unit 5 calculates the smoothed position and the smoothed speed of this time calculated as described above by the following mathematical formula 5,
Apply to _No. 6 and the next target predicted position (X _{pn + 1} ,
Y _{pn + 1} ) is calculated and given to the position smoothing processing unit 3 and the velocity smoothing processing unit 4. In Expressions 5 and 6, ΔT _{n + 1} is the next search time interval.

[0020]

[Equation 5]

[0021]

[Equation 6]

The time difference calculating unit 7 obtains the current track time from the track correlation processing unit 2 and calculates the difference between the track time and the previously obtained track time to obtain the current radar search time interval.
The detected detection time difference is given to the smoothing coefficient calculation unit 9.

The motion determination unit 8 determines the motion state of the aircraft based on the smoothed position data and the smoothed velocity data, that is, whether the motion is a constant-velocity linear motion or a turning motion (maneuvering condition). The index is given to the smoothing coefficient calculation unit 9.

The smoothing coefficient calculation unit 9 uses the smoothing coefficient (α, α) of the position and velocity used this time based on the distance R of the track from the radar installation position, which is input from outside the figure, the detection time difference, and the determination index. β) is calculated.

More specifically, the position smoothing coefficient α is a weighting coefficient that determines whether the predicted position or the target data acquired by the radar is important when determining the smoothed position. When it is determined that the maneuver is in motion, α is decreased, and when it is determined that the maneuver is in a turning motion, α is increased. At that time, the angle-measuring error differs depending on the distance from the radar installation position of the aircraft. Therefore, when the angle-measuring error is small, α is large, and when the distance is long, α is small to eliminate the influence of the angle-measuring error. ..

Further, as is clear from the equations 3 and 4, the velocity smoothing coefficient β has a time difference ΔT in the denominator, and if the detection time interval is short, it is greatly affected by the angle measurement error, and the smoothing velocity is The disturbance is as described above. Therefore, in the present invention, in consideration of the distance from the radar installation position to the aircraft, the detection time, and the motion state of the aircraft, β is increased as usual when the detection time interval is long, but is small when β is short. Calculate so that

[0027]

As described above, according to the track tracking processing device of the present invention, the smoothing coefficient of position and velocity is calculated based on the distance from the radar installation position of the aircraft, the detection time difference, and the motion state of the aircraft. It has a function to do. Therefore, the present invention can be applied to an electronic scanning type three-dimensional radar in which the scanning cycle is shortened or changed according to the search area, and even if the data rate of the target data becomes high, an appropriate smoothing coefficient corresponding to the data rate can be used. There is an effect that the accuracy of the smoothing position and the smoothing speed can be prevented from being deteriorated due to the increase, and the tracking can be stabilized even for an aircraft flying in a straight line.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a track tracking processing device according to an embodiment of the present invention.

[Explanation of symbols]

 1 coordinate conversion processing unit 2 track correlation processing unit 3 position smoothing processing unit 4 velocity smoothing processing unit 5 position prediction processing unit 6 tracking gate calculation processing unit 7 time difference calculation unit 8 motion determination unit 9 smoothing coefficient calculation unit

Claims (1)

[Claims] 1. Correlation of a track based on search data acquired by a three-dimensional radar and a tracking gate that is variably set, and a smoothed position is calculated from a position of the track where the correlation is obtained according to a smoothing coefficient of the position. In a track tracking processing device for calculating a smoothed velocity from a smoothed position according to a velocity smoothing coefficient; means for calculating a time difference between a previous time and a current time of a correlated track; the smoothed position and the smoothed Means for determining the motion state of the aircraft based on velocity and;
Means for calculating a smoothing coefficient of the position and the velocity based on a distance from the radar installation position of the aircraft, the time difference, and a motion state of the aircraft;