JP2006266901A - Method for calculating orientation position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an method for calculating orientation position having satisfactory precision, without increasing a scale of an orientation radar system. <P>SOLUTION: A plurality of capturing position information for a target such as a shell is acquired by the orientation radar system, An air drag coefficient and a drift coefficient for the target are calculated based on the capturing position information, and an orientation position of the target is calculated while applying the air drag coefficient and the drift coefficient in a trajectory equation, when calculating a trajectory by a sector method. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an orientation position calculation method in an orientation radar apparatus that captures a target such as a bullet that travels ballistically at high speed and calculates an orientation position such as a target launch position or landing position from the captured information.

  A beam curtain is formed by scanning the radar beam, and the target ballistic path is estimated from the position information when a target such as a bullet that is trajectory flying at high speed passes through this beam curtain, and the target launch position Alternatively, an orientation radar device that calculates a landing position (hereinafter referred to as an orientation position) is known (see, for example, Patent Document 1). In the orientation radar device disclosed in Patent Document 1, a beam curtain is formed by repeating scanning in a azimuth direction at a predetermined speed with a wide radar beam in a height direction, and a target such as a shell can While passing the curtain, acquisition information of a plurality of points including position information and time information is acquired for the target. Then, the orientation position is calculated based on the acquired capture information.

  When calculating the orientation position, first, trajectory calculation is performed to estimate the target trajectory in the section where the captured information of a plurality of points is obtained. This calculation requires position information and velocity information on the target trajectory. For position information, the position information in the captured information of multiple points, that is, the target direction and its distance are used as they are, and the velocity information Is obtained from, for example, position information and time information in adjacent captured information. Then, after performing ballistic calculation in the section corresponding to the captured information using these position information and velocity information, the orientation position is calculated by tracing the obtained trajectory back and forth.

  In this type of orientation radar apparatus, the arc division method is known as a method for calculating the trajectory and the target orientation position. In the arc dividing method, first, an approximate curve of a trajectory connecting the capture positions is calculated from the capture information of a plurality of target points, and a position and velocity vector at the midpoint are obtained. Next, using these as initial values, the target position is sequentially calculated at a predetermined time interval, that is, the arcing time. And the position where the altitude difference with the ground surface became smaller than the predetermined value is set as the orientation position.

An example of an orientation position calculation method using the above-described arc dividing method is disclosed (for example, see Patent Document 2). In the example of Patent Document 2, the time required for calculating the orientation position is particularly shortened by varying the arcing time.
JP-A-9-101363 (page 4, FIG. 1) JP 2002-277535 A (5th page, FIG. 1)

  By the way, since a shell flies while being affected by various effects including air resistance and wind, the flight trajectory is not necessarily a simple parabolic trajectory. In addition, how they are affected depends on the type of shell and makes the trajectory estimation more complicated. For this reason, in order to obtain a precise positioning result for the target launch position based on the trajectory calculation as described above, it is possible to launch as soon as possible after launch, that is, as much as possible. Target capture information near the location is required.

  However, in order to capture the target near the launch position, it is necessary to increase the gain of the radar device and make the detection distance longer. In particular, an increase in the size of the radar device is inevitable centering on the antenna portion. In addition, maneuverability was limited due to the increase in size.

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide an orientation position calculation method having good accuracy without increasing the scale of the orientation radar device.

  In order to achieve the above object, an orientation position calculation method of the present invention is an orientation radar apparatus that captures a target flying at high speed and calculates an orientation position such as a launch position or a landing position of the target from the captured information. An orientation position calculation method, wherein a radar echo reflected from the target is received to acquire the target capture position information at a plurality of capture points, and between the capture points from the capture position information of the adjacent capture points The target velocity vector is sequentially calculated, the acceleration vector between the capture points is sequentially calculated from the adjacent velocity vectors, and the velocity-air drag coefficient table and the velocity pair for the target are calculated based on the velocity vector and the acceleration vector. A drift coefficient table is generated, and the target air drag coefficient at each arcing point is determined by the arc dividing method from the farthest capture point. And and calculates the orientation position is performed ballistic calculations while the drift coefficients respectively acquired by referring to the speed versus air drag coefficient table and the speed versus drift coefficient table.

  According to the present invention, it is possible to obtain an orientation position calculation method having good accuracy without increasing the scale of the orientation radar apparatus.

  The best mode for carrying out the orientation position calculation method according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a flowchart showing an embodiment of the orientation position calculation method according to the present invention. FIG. 2 is a conceptual diagram showing an example of a scene in which the target position is calculated by applying this method. In FIG. 2, a bullet 1 that traverses the ball at high speed is captured at a plurality of capture points (capture points 1 to m) by the radar beam 3 of the orientation radar device 2, and the shell 1 is captured based on the captured position information. A scene in which the trajectory 4 is estimated and the shell firing position 5 is calculated is illustrated. Hereinafter, the orientation position calculation method in the scene illustrated in FIG. 2 will be described with reference to the flowchart of FIG.

  First, in a radar beam 3 formed by the orientation radar device 2, a shell 1 that traverses at high speed is captured at m capture points (capture point 1 to capture point m). This capture result is acquired as capture position information for each capture point. In the present embodiment, the capture position information is the distance R to the capture point, the azimuth angle θAZ and the elevation angle θEL of the capture point, and the capture time t. The captured position information acquired for each captured point is modeled and illustrated in FIG. 3 (ST11).

Next, the velocity vector Vn between these two points is sequentially calculated from the capture position information of the adjacent capture points to obtain V _{1 to} V _(m−1) . FIG. 3 illustrates the calculated velocity vector Vn as a model (ST12). Further, the acceleration vector αn between these two velocity vectors is sequentially calculated from adjacent velocity vectors to obtain α _{1 to} α _(m−2) . FIG. 3 illustrates the calculated velocity vector Vn and acceleration vector αn together (ST13).

  Subsequently, based on the velocity vector Vn and the acceleration vector αn calculated up to the previous step, a velocity-to-air drag coefficient table and a velocity-to-drift coefficient table for the shell 1 are generated. First, generation of a speed / air drag coefficient table will be described in detail with reference to the flowchart of FIG.

FIG. 4 is a flowchart showing an embodiment of a method for generating a speed / air drag coefficient table. Here, first, for each acceleration vector α _{1 to} α _(m−2) calculated in the immediately preceding step, an air drag is calculated based on a predetermined calculation formula (ST41). Next, this calculation result is made to correspond to the velocity vectors V _{1 to} V _(m−1) in the capture section (capture point 1 to capture point m) obtained in step ST12 described above, and the velocity as an actual measurement value The air drag coefficient table is graphed and drawn on a preset speed vs. air drag coefficient table. The graphed result is shown in FIG. 5 as a model. That is, in FIG. 5, a graph of air drag as an actual measurement value with respect to a speed range corresponding to the speed vector Vn is drawn on a speed vs. air drag coefficient table set in advance as illustrated by a bold solid line (ST42). .

  After obtaining the graph as the actual measurement value (thick solid line in FIG. 5), by evaluating the difference between this graph and the graph of the preset setting value (broken line in FIG. 5) using a statistical evaluation function, A correction coefficient for a preset setting value is calculated. The evaluation function at this time evaluates the variance of the difference between these two graphs, and the correction coefficient is derived so as to minimize this variance in the entire speed section including the acquisition section (ST43). .

  Then, by applying this correction coefficient to a preset velocity / air drag coefficient table, a velocity / air drag coefficient table for the shell 1 is generated. FIG. 6 illustrates a graph of a preset velocity / air drag coefficient table and a velocity / air drag coefficient table for the shell 1 generated by applying the correction coefficient. In FIG. 6, the graph of the set value set in advance is shown by a broken line, and the velocity versus air drag coefficient for the shell 1 generated by applying a correction coefficient thereto is shown by the solid line. It is a table (ST44).

Next, the generation of the velocity versus drift coefficient table will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart showing an embodiment of a method for generating a velocity versus drift coefficient table. The flow chart of FIG. 7 differs from the flow chart of the method for generating the velocity-to-air drag coefficient table illustrated in FIG. 4 in that, instead of the air drag, the firing of the shell 1 from each acceleration vector α _{1 to} α _(m−2). This is the point that the drift that is a component perpendicular to the direction is calculated. After the calculation of the drift, the same method as in FIG. 4 is used.

In the flowchart of FIG. 7, first, for each acceleration vector α _{1 to} α _(m−2) calculated in step ST13, a drift is calculated based on a predetermined calculation formula (ST71). Next, the calculation result is correlated with the velocity vectors V _{1 to} V _(m−1) in the capture section (capture point 1 to capture point m), and a velocity versus drift coefficient table as an actual measurement value is graphed in advance. Drawing on the set speed vs. drift coefficient table (ST72).

  After obtaining the graph as the actual measurement value, the difference between the graph and the graph of the preset setting value is evaluated by a statistical evaluation function, thereby calculating a correction coefficient for the preset setting value. The evaluation function at this time evaluates the variance of the difference between these two graphs, and the correction coefficient is derived so as to minimize this variance in the entire speed section including the acquisition section (ST73). . Then, by applying this correction coefficient to a preset velocity versus drift coefficient table, a velocity versus drift coefficient table for the shell 1 is generated (ST74).

  In this manner, a velocity-to-air drag coefficient table and a velocity-to-drift coefficient table for the cannonball 1 are generated (ST14).

  Thereafter, estimation of the trajectory 4 is started by setting the initial position of the arcing point and performing trajectory calculation by the arcing method. In the present embodiment, the initial position of the dividing point at which the calculation is started is set as the capturing point 1 which is the farthest capturing point from the orientation radar device 2 (ST15). In the arcing method, after setting each arcing point at a predetermined interval from this initial position, a ballistic equation applying a velocity-to-air drag coefficient table and a velocity-to-drift coefficient table for the shell 1 generated in step ST14 described above. Are used to calculate the position coordinates of the shell 1 at each arcing point sequentially from the initial position while referring to these tables. Then, the arc point where the altitude of the calculated position coordinates falls within a predetermined range is determined as the firing position 5 of the shell 1 (ST16).

  As described above, according to the present embodiment, the air drag coefficient and the drift coefficient for the target are acquired from the capture position information of the target such as a shell by the orientation radar apparatus, and the ballistic calculation by the arc division method is performed. The orientation position is calculated while applying these coefficients to the ballistic equation. Thereby, the trajectory of a target such as a shell can be estimated more accurately, and an orientation position calculation method having good accuracy can be obtained.

  In addition, since the trajectory can be estimated more accurately, it is not necessary to capture the target close to the launch position, especially when the launch position of a target such as a shell is used as the orientation position. Can be used. Therefore, it is not necessary to extend the detection distance of the orientation radar device. Thereby, it is possible to obtain an orientation position calculation method having good accuracy without increasing the scale of the orientation radar apparatus.

The flowchart which shows one Example of the orientation position calculation method which concerns on this invention. The conceptual diagram which shows an example of the scene which calculates the orientation position of a target by applying the orientation position calculation method which concerns on this invention. The figure which models and shows the acquired capture position information and the velocity vector and acceleration vector calculated from these. The flowchart which shows one Example of the production | generation method of a speed versus air drag coefficient table. The figure which models and shows the result by which the speed vs. air drag coefficient table as an actual measurement value was graphed on the preset speed vs. air drag coefficient table. The figure which models and shows the result of having graphed the speed-air drag coefficient table set beforehand and the speed-air drag coefficient table with respect to the shell 1 produced | generated by applying a correction coefficient. The flowchart which shows one Example of the production | generation method of a speed versus drift coefficient table.

Explanation of symbols

1 Cannonball 2 Orientation Radar 3 Radar Beam 4 Ballistic 5 Launch Position

Claims (5)

An orientation position calculation method in an orientation radar apparatus that captures a target flying at high speed and calculates an orientation position such as a launch position or a landing position of the target from this capture information,
Receiving radar echoes reflected from the target to obtain the target capture position information at a plurality of capture points;
Sequentially calculating the target velocity vector between these capture points from the capture position information of the adjacent capture points;
Sequentially calculating acceleration vectors between the capture points from the adjacent velocity vectors;
Based on the velocity vector and the acceleration vector, a velocity vs. air drag coefficient table and a velocity vs. drift coefficient table for the target are generated,
Ballistic calculation while acquiring the target air drag coefficient and drift coefficient at each arcing point from the farthest capture point by referring to the velocity vs. air drag coefficient table and the speed vs. drift coefficient table, respectively. To calculate the location position. When generating the velocity vs. air drag coefficient table,
Calculate air drag for each acceleration vector,
Create a velocity-air drag coefficient table as an actual measurement value in this speed range from the calculated air drag and the velocity vector,
Statistically evaluate the difference between the velocity-to-air drag coefficient table and the velocity-to-air drag coefficient table in a predetermined speed range set in advance using a predetermined evaluation function,
The orientation position calculation according to claim 1, wherein a correction coefficient calculated based on the evaluation result is generated by applying the correction coefficient to a speed-to-air drag coefficient table in the predetermined speed range set in advance. Method.   The predetermined evaluation function is to minimize a variance of a difference between a speed-to-air drag coefficient table as an actually measured value in the speed range and a speed-to-air drag coefficient table in a preset predetermined speed range. The orientation position calculation method according to claim 2, wherein: When generating the velocity versus drift coefficient table,
Calculate the drift for each acceleration vector,
Create a velocity vs. drift coefficient table as an actual measurement value in this speed range from the calculated drift and the velocity vector,
Statistically evaluate the difference between the speed vs. drift coefficient table and the speed vs. drift coefficient table in a predetermined speed range set in advance using a predetermined evaluation function,
4. The method according to claim 1, wherein the correction coefficient calculated based on the evaluation result is applied to a speed vs. drift coefficient table in the preset predetermined speed range. The orientation position calculation method according to item 1.   The predetermined evaluation function is to minimize a variance of a difference between a speed vs. drift coefficient table as an actually measured value in the speed range and a speed vs. drift coefficient table in a predetermined speed range set in advance. The orientation position calculation method according to claim 4.

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