JPH10177071A - Target tracking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a target tracking device that can track a target even when the target makes a sharp turn. SOLUTION: The target tracking device is provided with an observing means 3, which detects the information on a point to be observed viewed from an observation point or the relative position vector of a target and positional information on the displacement vector of the target and calculates the information on the displacement vector from the detected point to be observed or the information on the relative position vector or sets the information on the displacement vector by inputting the information on the detected displacement vector, an arithmetic means 4, which finds the turning radius and turning center of the target from the information on the past position of the target from the observing means 3 and predicts the information on the future position from the turning radium and turning center, and a displaying means 5, which displays the information on the predicted future position and the information on displacement vector from the observing means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target tracking apparatus for tracking a target using, for example, a radar.

[0002]

2. Description of the Related Art Radar (Radio detection and ranging)
) Is a radio observation device that emits a radio wave from its own transmitter, receives a reflected and returned radio wave with a receiver, detects a target, and measures a distance, an azimuth, and a moving speed. The target tracking device using such a radar or the like predicts a position to be observed this time (or the next time) by a straight line based on information on the position observed up to the previous time (or this time), and calculates the position of the previous time (or this time). ), If the correlation between the position obtained at the position observed this time (or the next time) is obtained under the preset conditions, the target tracking is continued as it is, and conversely, at these positions, When the position correlation cannot be obtained under the preset conditions, it is general to perform a process of making the subsequent target tracking disappear (hereinafter, lost).

[0003] For example, the turning performance of a ship tracked by a marine-monitoring radar installed on land is set (and designed) in advance in accordance with the ship, and for example, in accordance with the gross tonnage of the ship. It is as shown below.

[0004] Gross tonnage Turning radius (m) Turning rate (° / sec) Turning speed (m / s) Remarks 200,668 0.48,5.61 General vessels 100,573, 0.61 6.08 50,000 471 0.70 5.74 10,000 325 1.08 6.14 1,000 130 1.91 4.36 500 100 2.37 4.13 290 200 6.00 20.94 High-speed ship

[0005]

However, the conventional target tracking device utilizes the principle of radar and the fact that information on the position in the future can be obtained from information on the position observed in the past even if it is predicted by a substantially straight line. When tracking a target, information on the position in the future cannot be predicted by a straight line from information on the position observed in the past, and when the position is simply predicted by a straight line, There was a problem that the error became large.

[0006]

SUMMARY OF THE INVENTION A target tracking apparatus according to the present invention detects information on a relative position vector of a point to be observed or a target viewed from an observation point, and position information on a displacement vector, and detects the detected target. Based on the information on the relative position vector of the observation point or target, calculate the information on the displacement vector,
Or input information about the detected displacement vector,
The turning radius and the center position of the turn are obtained from the observation means for setting the information of the displacement vector and the information on the past position from the observation means, and the information on the future position is obtained from the information on the future radius and the center of the turn. The information processing apparatus includes a calculating means for predicting the position based on the position, and a display means for displaying tracking information of the target by using information on a future position predicted by the calculating means and information on a displacement vector by the observing means.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a target tracking device according to one embodiment of the present invention. In the figure,
Reference numeral 1 denotes, for example, a radar device of a type that rotates a general antenna or information on a relative position vector of a point to be observed or a target viewed from an observation point by a manual instruction using a keyboard, and position information on a relative velocity vector (displacement vector). The input position information input means 2 calculates relative velocity vector (displacement vector) information based on the relative position vector information of the observation point or the target input from the position information input means 1, or inputs position information. This is displacement information setting means for inputting position information on a relative velocity vector (displacement vector) from the means 1 and setting information on these displacement vectors. The position information input means 1 and the displacement information setting means 2 use the observation means 3 Is composed.

[0010] 4 obtains the turning radius and the center position of the turning from the information on the past position from the observation means 3,
The calculating means 5 for predicting the information on the future position based on the turning radius and the center position of the turning, and the target 5 uses the information on the future position predicted by the calculating means 4 and the information on the displacement vector by the observation means 3. Display means for displaying tracking information.

Next, the operation of this embodiment will be described. First, the closest approach distance CPA and the closest approach distance arrival time T
CPA will be described. FIG. 2 is an explanatory diagram for explaining the closest approach distance CPA and the closest approach distance arrival time TCPA. In FIG. 2, for simplicity, for example, the observation position is A, the monitored position is B, and the relative position vector of B viewed from A is L = (X, Y) (the components in the x direction are X, y
The component of the direction is Y), and the relative velocity vector of B viewed from A is M = (U, V) (the component in the x direction is U, and the component in the y direction is V).

In the relationship shown in FIG. 2, the closest approach distance CPA and the closest approach distance arrival time TCPA are calculated by the following equations.

(When U ² + V ² = 0) (when U ² + V ² ≠ 0) CPA = (X ² + Y ² ) ^1/2 | XV-YU | / (U ² + V ² ) ^1/2 TCPA = undefined - (XU + YV) / ( U 2 + V 2)

In order to calculate the closest approach distance CPA and the closest approach distance arrival time TCPA, information on the accurate monitored position B and information on the future position are required.

Next, prediction of future position information in this embodiment will be described. FIG. 3 is an explanatory diagram for explaining prediction of future position information according to this embodiment.

Here, in general, when the three-dimensional distance and time space is represented by a coordinate system of XYZ and t, the relative position vector of the observation point P viewed from the observation point O at the time t is R = r ( t) = (x, y, z), and the relative position vector at time t + dt is R ′ = r (t + dt) = (X
+ Dx, Y + dy, Z + dz), the relative movement vector (displacement vector) of the position of the observation point P as viewed from the observation point O is DR = dr (dt) = (dz, d
y, dz). In FIG. 3, the position is indicated on the XY plane for simplicity of description.

First, the turning radius R is the distance of a line segment PQ that passes through the terminal position P of the relative position vector r (t) at time t and intersects the relative velocity vector at right angles, and the center position Q of the turning is , Generally starting at position P,
A line segment PP 'passing through the midpoint S of the line segment terminating at the position of the terminal position P' of the relative position vector at the time (t + dt)
Is the position of the intersection of the line segment SQ and the line segment PQ that intersect at right angles. In the case where both straight lines obtained by extending these line segments do not intersect (become parallel lines), in this embodiment, for example, the position of a point at infinity in the rightward direction from the start end to the end, for example, is set. Is Q.

As described above, in the present embodiment, unlike the conventional prediction method using a straight line, the prediction method based on turning (curve) is used as a base, and the position / displacement vector at time (t) is calculated. Based on the turning radius and the center position of the turning, the turning is basically performed at the time (t + d
The position / displacement vector at t) is predicted.

As a result, as shown in FIG. 3, when the error between the conventional predicted azimuth and the actual azimuth is maximized, the error in the present embodiment is less than half that of the conventional azimuth, and indicates the actual position and azimuth. It is strange. As described above, in this embodiment, it is possible to reduce the prediction error as compared with the conventional case where the prediction is performed by using a straight line.

Here, referring to FIG. 3, a case where the movement amount of the observation position obtained at the previous time and the movement amount of the observation position obtained at the current time are changed will be described. FIG. 4 is an explanatory diagram for explaining the relationship between a predicted value such as a position and the observed value. FIG. 4A shows a case where only the moving speed of the position changes with acceleration, and FIG. b) shows a case where the course and speed of the position have changed. As shown in FIG. 4, the azimuth (heading) toward the position where the distance from the predicted position to the observation position is the shortest distance is calculated, thereby specifying the moving direction from the predicted position. Also, in this case,
Since there is no change in the course after the elapse of the preset time, the course value predicted at the previous time is the course value observed as it is.

The same applies to the case where only the course changes, and only when the value of course C changes to C ', the direction heading toward the position that is the shortest distance between the predicted position and the observation position is the course C. 'Is obtained. Further, in this case, since there is no change in the speed even after the lapse of the preset time, the value of the speed predicted at the previous time is the value of the observed speed as it is.

The same applies to the case where the course and the speed change, and by calculating the azimuth (the course) toward the position where the distance from the predicted position to the observation position is the shortest distance,
The direction of movement from the predicted position is specified. here,
In FIG. 4, the possible range of the predicted position and the observation position at time N is indicated by a solid line and a broken line sector for reference.

In this embodiment, the target tracking device using, for example, a radar has been described. However, the present invention may be applied to an observation device other than the radar.

[0022]

As described above, according to the present invention, the turning radius and the center position of the turn are obtained from the information on the past position from the observing means, and the information on the future position is obtained by the calculating means. Since the prediction is made based on the turning radius and the center position of the turning, even when the ship that is going straight turns suddenly, it can follow the turning of the ship well and track, and the actual target Since the position and the displacement vector to be predicted and made to follow so as to coincide with the turning of the object are both rotated, the error with the actual position and the displacement vector is reduced, and the effect that the tracking can be performed with high accuracy can be performed. Have.

[Brief description of the drawings]

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

FIG. 2 Closest distance CPA and closest distance arrival time TCP
FIG. 3 is an explanatory diagram for explaining A.

FIG. 3 is an explanatory diagram for explaining prediction of future position information according to the embodiment;

FIG. 4 is an explanatory diagram for explaining a relationship between a predicted value such as a position and an observed value.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Position information input means 2 Displacement information setting means 3 Observation means 4 Calculation means 5 Display means

Claims (3)

[Claims] 1. A method for detecting information on a relative position vector of an observed point or a target viewed from an observation point and position information on a displacement vector, and based on the detected information on a relative position vector of the observed point or a target. Observing means for calculating information on the displacement vector, or inputting information on the detected displacement vector, and setting the information on these displacement vectors, From the information on the past position from the observing means, the turning radius and Calculating means for determining the center position of the turn and predicting information on the future position by the turning radius and the center position of the turn; information on the future position predicted by the calculating means and displacement vectors of the observation means Display means for displaying target tracking information using the information. 2. The arithmetic means, when the three-dimensional distance and time space is represented by a coordinate system of XYZ and t, calculates a relative position vector of the observation point P viewed from the observation point O at time t as R = r (t) = (x, y, z) and time t + dt
R ′ = r (t + dt) =
Assuming that (X + dx, Y + dy, Z + dz), the displacement vector of the position of the observation point P viewed from the position of the observation point O is DR = dr (dt) = (dz, dy, dz). Then, the turning radius R at that time is defined as a distance between a line segment PQ passing through the observed point P and intersecting at right angles with the displacement vector of the position of the observed point P at the time t, that is, the terminal position of the relative position vector r (t). The center position Q of the turn at this time is defined as the time (t
+ Dt), the turning radius and the turning radius are defined as the positions of the intersections of the line segment SQ and the line segment PQ passing through the midpoint S of the line segment ending at the position of the terminal position P ′ of the relative position vector and intersecting the line segment PP ′ at right angles. 2. The target tracking device according to claim 1, wherein the target position is obtained for a center position of the turn. 3. When calculating the center position Q of a turn, when the line segment SQ and the line segment PQ are parallel lines and do not intersect with each other, the calculating means determines the position of a point at infinity in a preset direction to determine the position of the turn. 3. The target tracking device according to claim 2, wherein the target position is set to a center position Q.