JP2002174499A - Target future position estimation method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a target future position estimation method and device for estimating the future position of a target with a high accuracy by a relatively simple calculation. SOLUTION: The target B is tracked by a target position sensor 1 for acquiring a current target position from moment to moment, a current target position signal obtained by the target position sensor 1 is converted to a coordinates position by a data-recording section 3 and is recorded along with measurement time, a complementary function is calculated by a complementary function calculation section 4 based on the target position signal from moment to moment by a complementary function calculation section 4 based on the target position signal from moment to moment from the data-recording section 3, the function of firearms flight time required for the impact of firearms 8 after future time is calculated by a firearms trajectory calculation section 5, and the future position of the target where the firearms 8 crosses the target after future time is calculated based on a complementary function signal from the complementary function calculation section 4 and a firearms flight time signal from the firearms trajectory calculation section 5 by a future position calculation section 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target future position estimating method and a target position estimating device for estimating a target future position with high accuracy.

[0002]

2. Description of the Related Art As a conventional apparatus for estimating the future position of a target, there is a future position calculating apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 59-44598 and schematically shown in FIG.

[0003] This future position calculating apparatus is used to move a target 1
Radar 101 for tracking 00, tracking calculation device 10
2. Shooting calculation device 103, delay device 104, future position error calculation device 105, display device 106, future position error correction device 107, future position error input switching device 108, input device 109, and bullet toward the future position of target 100. Has a firearm 110 that fires.

[0004] By tracking the target 100 by the tracking radar 101, a target current position is obtained every moment. The obtained target current position is sent to the tracking calculation device 102 as a current position signal 111, and the tracking calculation device 102 calculates the moving direction and the speed of the target 100 from the current position signal 111, and together with the current position signal 111, the target 100 Is sent to the shooting calculation device 103.

Here, the shooting calculation device 103 includes a firearm 110
The position at which the target 100 and the bullet meet, assuming that the target position changes but the moving direction and speed of the target 100 do not change in the elapsed time until the bullet reaches the target 100 by firing the bullet, that is, The future position is calculated and the future position signal 11 is calculated.
4 as delay device 104 and future position error correction device 107
And the bullet time-of-flight signal 115 at the same time
Send to 4.

The delay device 104 delays the bullet flight time of the future position signal 114 and sends it to the future position error calculation device 105 as a delayed future position signal 116. The tracking calculation device 102 also sends the current position signal 111 to the future position error calculation device 105. The future position error calculation device 105 calculates the future position error by subtracting the current position signal 111 from the delayed future position signal 116, and sends it to the display device 106 and simultaneously sends it to the future position error input switching device 108.

[0007] The future position error input switching device 108 is a future position error signal 1 input to the future position error correction device 107.
17 is the future position error calculating device 105 or the input device 10
This is a device for switching whether to input from 9 or not, and sends a future position error signal 117 to the future position error correction device 107. The future position error correction device 107 calculates a corrected future position by automatically adding the future position error signal 117 to the future position signal 114, and sends the corrected future position signal 118 to the firearm 110.
The firearm 110 fires a bullet at the obtained corrected future position.

[0008]

According to the apparatus shown in FIG. 9, even when the target 100 reaches the current position by changing the moving direction by performing a circular motion or the like during the bullet flight time, the future position error is added to the future position. In addition, the corrected future position can be calculated, and the firearm 110 can be fired toward the corrected future position, so that the hit rate of the bullet can be improved.

However, when predicting the target future position, the radar 101 detects the position and speed of the target 100, and estimates the future position by assuming that the moving direction and speed do not change. From the estimation, the actual target 1 where the acceleration changes moment by moment
In many cases, the estimation of the future position of 00 is incorrect. On the other hand, it is difficult to accurately estimate the rate of change of the acceleration that determines the future moving direction of the target 100. This is because the data of the estimated acceleration must be obtained by differentiation, and the tracking radar 1
This is because there is a high possibility that a large error is included due to a sensor error such as 01 or noise.

Accordingly, an object of the present invention, which has been made in view of the above points, is to provide a target future which can estimate a target future position with high accuracy by relatively simple calculation without requiring calculation of speed, acceleration, acceleration change rate, and the like. A position estimation method and a target position estimation device are provided.

[0011]

According to a first aspect of the present invention, there is provided a target future position estimating method for obtaining a target position every moment and estimating a target future position. Calculating a complementary function using a single curve passing through a plurality of positions of the target trajectory as a function of time, calculating a function of a firearm flight time required for landing of a firearm after a future time, and calculating a function after the future time. The present invention is characterized in that a position at which the complement function and the function of the firearm flight time intersect is estimated as a future position of the target.

According to the first aspect of the present invention, the future position is estimated from a complementary function that makes one continuous curve passing through a plurality of positions on the movement trajectory of the target as a function of time and a function of the firearm flight time. Can be estimated with higher accuracy than the conventional estimation method of estimating the future position on the assumption that the moving direction and the speed of the moving image do not change. In addition, high estimation accuracy can be obtained by relatively simple calculation without requiring cumbersome calculations for estimating speed, acceleration, and the rate of change of acceleration.

According to a second aspect of the present invention, there is provided a target future position estimating method for estimating a future position of a target by obtaining an instantaneous target position. The position is acquired, the target current position is converted into a coordinate position, recorded with the measurement time, and one curve passing through a plurality of positions of the target trajectory based on the coordinate position at each time is defined as a function of time and Calculating the function of the firearm flight time required for the landing of the firearm after a future time, and estimating the position where the complement function and the function of the firearm flight time intersect after the future time as the future position of the target. It is characterized by doing.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, in addition to the first aspect of the present invention, a target is tracked to obtain a target current position every moment. The target current position is converted into a coordinate position, recorded together with the measured time, and the complementary function is calculated based on the coordinate position at each time, whereby the complementary function can be calculated more easily.

According to a third aspect of the present invention, in the target future position estimating method according to the first or second aspect, the complementary function is:
It is obtained as a spline function.

According to the third aspect of the present invention, the future position can be easily and accurately estimated by using a spline function for obtaining an approximate value of the complementary function at the end of a series of partial sections with high accuracy.

According to a fourth aspect of the present invention, there is provided a target future position estimating apparatus for estimating a future position of a target by tracking a target with a target position sensor and obtaining a momentary target position. A target position sensor that obtains a momentary target current position by tracking the target; a data recording unit that converts a target current position signal from the target position sensor into a coordinate position and records the coordinate position along with a measurement time; A complementary function calculating unit that calculates a complementary function having a single curve passing through a plurality of positions of the target movement trajectory as a function of time based on a target position signal at each time, and a firearm required to land the firearm after a future time A firearm trajectory calculation unit for calculating a function of flight time,
A future position calculating unit that calculates a future position of a target at which the firearm and the target intersect with each other after a future time based on the complementary function signal from the complementary function calculating unit and the firearm flight time signal from the firearm trajectory calculating unit. It is characterized by the following.

According to a fourth aspect of the present invention, there is provided a target future position estimating apparatus for performing the target future position estimating method according to the first and second aspects, wherein the target position is tracked by a target position sensor and is constantly changed. The target current position is obtained, the target current position signal obtained by the target position sensor is converted into a coordinate position by the data recording unit, recorded together with the measurement time, and based on the target position signal for each time from the data recording unit. The complement function calculation unit calculates a complement function using a single curve passing through a plurality of positions of the target movement trajectory as a function of time, while the firearm trajectory calculation unit calculates the firearm flight time required for the arrival of a firearm after a future time. Calculates the function, and the future position calculation unit uses the complement function signal from the complement function calculation unit and the firearm flight time signal from the firearm trajectory calculation unit to calculate the future of the target where the firearm and the target intersect. By calculating the location, it is possible to perform a target future estimation method of the claims 1 and 2.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a target future position estimation method and a target position estimation device according to the present invention will be described with reference to FIGS.

As shown in FIG. 1 and a block diagram in FIG. 2, the present target future position estimating method tracks a target B by a target position sensor such as a tracking radar mounted on its own machine A, for example. The target current position data, which changes moment by moment, is recorded, a complementary function is calculated based on the target position data, and the target future position of the target B and the flight time of the firearm fired from the own aircraft A are calculated by the complementary function. It calculates and estimates the future position where the target and the firearm meet.

The target future position estimating method and the target position estimating apparatus will be specifically described with reference to FIGS.

FIG. 3 is an explanatory view showing an outline of a target future position estimating method (this estimating method) and a target position estimating apparatus according to the present embodiment. FIGS. 4 to 6 show a constant acceleration estimating method (a conventional estimating method). FIG. 7 is an explanatory diagram comparing the estimation accuracy of the future position by the present estimation method with the estimation accuracy of the future position by the present estimation method.

In the drawing, reference numeral 1 denotes a target position sensor such as a tracking radar for tracking a moving target B, 2 denotes a clock for recording the time measured by the target position sensor 1, and 3 denotes a time series of measured data. A data recording unit for recording, 4 is a complement function calculating unit for obtaining a complementary function from the recorded data, 5 is a firearm trajectory calculating unit for calculating a firearm flight time from launch to impact, and 6 is a three-dimensional position in future time. Is a future position calculation unit that outputs the following.

Next, the operation will be described. By tracking the target B by the target position sensor 1 such as a tracking radar, the azimuth Γ, the depression angle Ψ, and the distance R of the target current position with respect to the own machine A are obtained every moment. The azimuth angle Γ, depression angle Ψ, and distance R of the obtained target current position are the target current position signal 1
1 is sent to the data recording unit 3 together with the time signal 12 from the clock 2, and the data recording unit 3 outputs the azimuth angle Γ, depression angle Ψ,
The distance R is converted into the three-dimensional coordinate positions X, Y, and Z of the target B and recorded together with the measurement time T. This coordinate transformation method is obtained by Euler transformation in which rotation transformation is performed using the azimuth angle Γ and the depression angle Ψ.

The target position for each time converted into the coordinate positions X, Y, and Z is sent to the complementary function calculating section 4 as a target position signal 13 for each time, and the complementary function calculating section 4 obtains a complementary function.

At the same time, an azimuth angle Γ, a depression angle Ψ, and a distance R
Is sent to the firearm trajectory calculation unit 5, and the firearm trajectory calculation unit 5 calculates the firearm flight time t required from the firing of the firearm 8 to the future position. Sent as time signal 15.

The complementary function unit 4 obtains a complementary function in which one continuous curve passing through a plurality of positions on the trajectory of the target B is a function of time. An example of extrapolation by a spline function will be described below as an example of calculation of the complement function.

An example of a spline function in which the differential value up to the second order at each measurement position at the position coordinate x is shown. Time t
An approximation function between _i and t _{i + 1} is set as follows. x (t) = x _i + a _i (t−t _i ) + b _i (t−t _i ) ² + c
_i (t-t _i) ³ is the differential value up to the secondary _{dx / dt = a i + 2b} i (t-t i) + 3b i (t-t
^{_{i) 2 d 2 x / dt}} 2 = 2b i + 6c i (t-t i) by the connection condition at _{t = t i + 1 x i} + a i h i + b i h i 2 + c i h i 3 = x i _{+1 a i + 2b i h i} + 3c i h i 2 = a i + 1 2b i + 6c i h i = 2b i + 1 where, from this _{hi = t i + 1- t i} , a i, b i, c _{i i} = 1. . . A simultaneous linear equation for n-1 (n is the total number of discrete data) is derived. By solving this, a spline function x (t) is obtained. Similarly,
The spline functions y (t), z are also used for the position coordinates y, z.
Find (t).

On the other hand, the firearm trajectory calculation unit 5 obtains the firearm flight time Δt required for landing. The formula for calculating the firearm flight time is obtained by, for example, firearm flight time Δt = (distance to target) / (firearm speed). In the trajectory calculation by the firearm trajectory calculation unit 5,
Calculates the firearm flight time Δt to the future position,
Since the future position to be used first has not been determined yet, it is temporarily calculated using the target current position.

Spline functions x (t), y (t), z
(T) That is, the complementary function and the firearm flight time Δt are sent to the future position calculation unit 6 as the complementary function signal 16. As a result, the future position after the firearm flight time Δt is obtained by the future position detection unit 6 using the spline functions x (t), y (t), and z (t).

The future position obtained by the future position detector 6 is transmitted to the firearm trajectory calculator 5 as a target future position signal 17 and used for calculating the function of the firearm flight time Δt. This complementary function is a continuous curve passing through a plurality of positions determined by the target position sensor 1, and a smoothly continuous function is selected at each measurement point. A curve close to an image extending the wake of the target B is obtained, and the intersection of the complementary function and the function of the firearm flight time meets the target B and the firearm 8. Target future position.

The calculation of the complementary function by the complementary function calculator 6 for creating the complementary function is performed every time data such as the azimuth angle Γ, the depression angle Ψ, and the distance R input from the target position sensor 1 is input from time to time. The future position estimation calculation is constantly performed and updated in accordance with the calculation rate of the firearm trajectory calculation unit 5 so that the firearm 8 may be fired at any time.

FIG. 4 shows a target B in a 2G turning slalom at an initial speed of 100 kt with a large acceleration change during turning.
FIG. 7 is an estimation accuracy error comparison diagram comparing the estimation error of the future position by the present estimation method with the estimation error of the conventional estimation method, that is, the estimation error of the constant acceleration estimation method that calculates that the measured acceleration will continue in the future in that state. . In the figure, a circle indicates a true value indicating the actual movement of the target B, a cross indicates an estimated future position by the present estimation method, a triangle indicates an estimated future position by the conventional estimation method, and a subscript indicates data. The acquisition timing is shown.

As is clear from the estimation accuracy error comparison diagram, according to the conventional estimation method indicated by the symbol in the figure, the future position estimation spreads out of the actual turning circle indicated by the symbol with time with the passage of time. According to the present estimation method indicated by a + sign, a value close to a turning circle is output, and the present estimation method can significantly improve the future position estimation accuracy compared to the conventional estimation method. You can see that. At this time, the average of the estimation error by the conventional estimation method is 49 m, while the average of the estimation error is 32 m by the present estimation method, and the error improvement rate is improved by about 34%.

FIGS. 5 to 7 are estimated error comparison diagrams showing a correlation between an acquired data interval per turn and an error improvement rate in a 2G turn slalom in which the target G has an initial speed of 100 kt.

FIG. 5 is a comparison diagram of an estimation error comparing the estimation error when the average number of data per turn of the target B is 7.1, and FIG. 6 is a graph when the number of data per turn is 4.2. FIG. 6 is a comparison diagram of estimated speed error of FIG. In the figures, a circle indicates a true value indicating actual movement of a target, a cross indicates an estimated future position by the present estimation method, and a triangle indicates an estimated future position by a conventional estimation method.

Average number of data per turn shown in FIG.
The average of the estimation error by the conventional estimation method at 1 is 5.9.
m, whereas the average of the estimation errors by this estimation method is 4.
6 m, and an improvement in the error improvement rate of about 22% was obtained.
On the other hand, when the average number of data per turn shown in FIG. 6 is 4.2, the average estimation error by the conventional estimation method is 18.5 m, whereas the average estimation error by the present estimation method is 20.
2 m, and the error improvement rate was about -9.7%.
FIG. 7 shows an error improvement rate obtained by comparing the average estimation error by the present estimation method with the average estimation error by the conventional estimation method with respect to the average number of data per turn.

Therefore, when the number of acquired data is smaller than that of the turning circle, the estimation accuracy of the present estimation method becomes worse as compared with the conventional estimation method (up to the data acquisition timing 4 in FIG. 4 and FIG. 5).
Data number of 4.2 to 7 or less). However, the target position sensor 1 such as a tracking radar can input data of the current position of the target B at least at several Hz or more, and when the target is an aircraft, it flies at high speed while repeating a large turn every few seconds. This is difficult, and it is rare that the number of acquired data is less than five. In general, a more accurate future position estimation can be obtained as compared with the related art. For example, assuming a helicopter capable of relatively small turns as the target B, a flight speed of 100 kt
The turning radius required for the G-balance turning is about 156 m, and it takes about 9.5 seconds to make a half turn of this turning. Even if the user flies out of balance using sideslip due to the avoidance maneuver, if the turning steering is repeated within a few seconds, it is substantially the same as the case of a straight flight, and the present estimation method can provide a sufficiently high-accuracy future position estimation.

Furthermore, even for a random walk in which the future movement of the target B has an acceleration change that cannot be predicted at all, a future position can be estimated with higher accuracy than the conventional estimation method. FIG. 8 is an estimation accuracy error comparison diagram comparing the estimation error when the number of data per turn is 4 between the present estimation method and the conventional estimation method in a random walk of MAX2G at an initial speed of 100 kt, and FIGS. Similarly, in the figure, a circle indicates a true value indicating actual movement of a target, a cross indicates future position estimation by the present estimation method, and a triangle indicates future position estimation by a conventional estimation method.

The average estimation error by the conventional estimation method is 11
m, the estimated error average is 8 m according to the present estimation method, and an improvement in the error improvement rate of about 23% is obtained. In the random walk, a higher future position estimation than the conventional estimation method is obtained. It is confirmed that it can be obtained.

Therefore, according to the present estimation method, the target current position data which changes every moment by tracking the target B by the target position sensor 1 such as a tracking radar is recorded, and the spline function is used based on the target position data. Since the complementary function is calculated and the future position is estimated by calculating the target future position and the flight time Δt of the firearm 8 from the movement trajectory of the target B by the complementary function, it is assumed that the moving method and the speed of the target do not change. It is possible to estimate the future position with higher accuracy as compared with the conventional constant acceleration estimation method for estimating the future position. In addition, since the future position is estimated from the movement trajectory and the firearm flight time using the complementary function, high estimation accuracy can be obtained by a relatively simple calculation without the need for complicated calculations for estimating the speed, acceleration, and rate of change of acceleration. Can be

The present invention is not limited to the above embodiment, but can be variously modified without departing from the gist of the present invention. For example, in the above-described embodiment, the case of estimating the target future position with respect to the own device A has been described as an example. However, estimating the target future position from a fixed point such as the ground can provide high estimation accuracy by the same estimation method. In addition, as a complementary function used for calculating the future position, a complementary function that can calculate a curve having a plurality of positions on the target movement trajectory can be used.

[0043]

According to the target future position estimating method of the present invention described above, the target future position and the firearm flight time can be obtained from the movement trajectory obtained by the complementary function using a curve passing through a plurality of positions of the target movement trajectory as a function of time. By estimating the future position from the function, the future position can be estimated with higher accuracy than the conventional estimation method that estimates the future position assuming that the moving direction and speed of the target do not change. In addition, high estimation accuracy can be obtained by relatively simple calculation without requiring cumbersome calculations for estimating speed, acceleration, and the rate of change of acceleration.

According to the invention of the target future position estimating apparatus, the target current position is obtained every moment by the target position sensor, and the target current position signal obtained by the target position sensor is converted into the coordinate position by the data recording unit. The time is recorded together with the measured time, and based on the target position signal at each time, the complement function is calculated by the complementary function calculation unit, while the firearm trajectory calculation unit calculates the function of the firearm flight time required for the landing of the firearm after a future time Then, the future position calculation unit calculates the future position of the target based on the complementary function signal and the firearm flight time signal, whereby the target future estimation method can be executed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of an embodiment of a target future position estimation method according to the present invention.

FIG. 2 is a block diagram showing an outline.

FIG. 3 is an explanatory diagram of a future position prediction calculation configuration showing an overview.

FIG. 4 is an estimation error comparison diagram comparing the estimation accuracy of the future position by the estimation method according to the present embodiment with the estimation accuracy of the future position by the conventional constant acceleration estimation method.

FIG. 5 is an explanatory diagram comparing the estimation accuracy of the future position by the estimation method according to the present embodiment with the estimation accuracy of the future position by the conventional constant acceleration estimation method.

FIG. 6 is an estimation error comparison diagram comparing the estimation accuracy of the future position by the estimation method according to the present embodiment with the estimation accuracy of the future position by the conventional constant acceleration estimation method.

FIG. 7 is an explanatory diagram showing an error improvement rate obtained by comparing the estimated error average by the present estimation method and the estimated error average by the conventional estimation method with respect to the average number of data per turn.

FIG. 8 is a comparison diagram of the estimation error comparing the estimation accuracy of the future position by the estimation method according to the present embodiment with the estimation accuracy of the future position by the conventional constant acceleration estimation method.

FIG. 9 is a schematic explanatory diagram of a conventional future position calculating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Target position sensor 2 Clock 3 Data recording part 4 Complementary function calculating part 5 Firearm trajectory calculating part 6 Future position detecting part 8 Firearm 11 Target current position signal 12 Time signal 13 Target position signal 14 Target position signal for initial trajectory calculation 15 Firearm flying Time signal 16 Complementary function signal 17 Target future position signal A Own machine B Target

Claims (4)

[Claims] 1. A target future position estimating method for estimating a future position of a target by obtaining a target position every moment, wherein a complementary function having a curve passing through a plurality of positions of the target moving trajectory as a function of time is provided. Calculating and calculating a function of a firearm flight time required for landing of a firearm after a future time, and estimating a position where the above-mentioned complementary function and a function of the firearm flight time intersect after a future time as a future position of a target. Target future position estimation method. 2. A target future position estimating method for estimating a future position of a target by obtaining an instantaneous target position, wherein the target is tracked to obtain an instantaneous target current position, and the target current position is converted to a coordinate position. Converted and recorded together with the measurement time, and based on the coordinate position at each time, calculate a complementary function using one curve passing through a plurality of positions of the target trajectory as a function of time. Calculating a function of a firearm flight time required for landing of the target, and estimating, as a future position of the target, a position where the complementary function intersects the function of the firearm flight time after a future time. 3. The target future position estimating method according to claim 1, wherein the complementary function is obtained as a spline function. 4. A target future position estimating apparatus for tracking a target with a target position sensor to obtain a momentary target position and estimating the future position of the target, wherein the target is tracked to obtain a momentary target current position. A target position sensor, a data recording unit that converts a target current position signal from the target position sensor into a coordinate position and records the coordinate position together with the measurement time, and moving the target based on the target position signal for each time from the data recording unit. A complementary function calculating unit that calculates a complementary function that uses one curve passing through a plurality of positions of the trajectory as a function of time; a firearm trajectory calculating unit that calculates a function of a firearm flight time required for landing of a firearm after a future time; A future position calculation unit that calculates a future position of a target at which a firearm and a target intersect a future time after the future time based on the complementary function signal from the complementary function calculation unit and the firearm flight time signal from the firearm trajectory calculation unit. Target future position estimating device characterized by comprising a.