JP2775986B2 - Radar equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a radar apparatus that scans the entire covered area with a search beam and tracks a plurality of detected targets with corresponding tracking beams. Tracking technology when there is no radar response from the system.

(Prior Art) As shown in FIG. 1, a radar apparatus to which the present invention is applied searches for a search beam (marked with a circle in the figure) every radar scan.
Scans the entire area within the area, and tracks the detected multiple targets. To track.

By the way, in the conventional radar apparatus, with respect to the emission timing of both beams, for example, as shown in FIG. 5, the emission timing of the search beam S is continuously defined in order from the head position in one radar scan, and thereafter, a predetermined number of Tracking beam T _i
The firing timing of (i = 1 to n) is continuously defined, and the processing related to tracking is performed by a target processing unit as shown in FIG. 6, for example.

In FIG. 6, the target processing unit is provided between the target detection unit and the beam control unit, and is basically configured by a target tracking circuit 1 in the preceding stage and a predicted position effecting circuit 2 in the subsequent stage.
The target tracking circuit 1 includes a tracking processing circuit 11b and a track data management circuit 12.

The target detection unit detects a target based on the radar information received by the antenna, calculates the position information, and outputs the position information to the tracking processing circuit 11b.

The tracking processing circuit 11b obtains the past position information of the target from the track data management circuit 12, compares it with the position information input from the target detection unit, calculates the current target smooth position and speed, and calculates The calculated current target position and speed, track number (target identification number), and information on the target are output to the predicted position calculation circuit 2. Here, the information on the target is information necessary to determine whether the target is a target for continuing or ending tracking, or a target for starting a new tracking.

Prediction position calculation circuit 2, its target from the current position and velocity input predicts the position reached in the next radar scan, (either T ₁ through T _n) beam number to the location information
And a track number and the like, and outputs the result to the beam control unit. At the same time, this information is output to the track data management circuit 12 as the next tracking information, and the information is updated.

The beam control unit emits the tracking beam in the designated direction at the timing of the designated beam number.

(Problems to be Solved by the Invention) In the above-described conventional radar apparatus, if the emission timing of the tracking beam is scheduled near the end of one radar scan, for example, as shown in FIG. Measurement of the target position for the beam will be performed in the next radar scan. Then, when a radar response cannot be obtained from the expected target, an error occurs between the direction of the tracking beam to be directed in the next radar scan (calculated using the position information of the past target) and the actual direction. This error becomes a considerable difference when the target acceleration is large. If the difference between the directions is larger than the angle of the tracking beam capable of detecting the target, there is a problem that the target cannot be detected and the tracking cannot be continued.

In order to solve this problem, it is necessary to enable the tracking beam to be emitted again to the same target within one radar scan. However, in the conventional radar apparatus, as shown in FIG. 5, the emission timing of the tracking beam is temporally concentrated at a specific location within one radar scan, so that a radar response is obtained from an expected target. Even if an attempt is made to re-emit the tracking beam, the time given to the tracking beam may be exceeded in consideration of the processing time of the circuit, so that it is necessary to wait until the next radar scan, and the above problem cannot be solved.

The present invention has been made in view of such a problem, and an object of the present invention is to enable a tracking beam to be emitted again in a radar scan when a radar response cannot be obtained from an expected target, thereby improving tracking accuracy. It is to provide a radar device that can be achieved.

(Means for Solving the Problems) In order to achieve the above object, a radar device of the present invention has the following configuration.

That is, the radar device of the present invention is a radar device that scans the entire coverage area with a search beam in one radar scan and tracks a plurality of detected targets with a corresponding tracking beam; a fixed number of searches in one radar scan The launch timing of the beam and the launch timing of one tracking beam are alternately defined; by referring to the obtained beam number management information, at least the launch timing of the tracking beam already used as the tracking beam for the new target is determined. Designating a tracking beam at the next emission timing, and when no radar response can be obtained from an expected target, changing and specifying an unused tracking beam at the emission timing after the emission timing of the tracking beam specified for the target. Means for outputting beam number change information relating to the designated tracking beam; The device manages a combination of a track number of a target tracked by the target device and a tracking beam number designated to the target, and outputs the beam number management information in response to a request. Means for updating the management content according to the number change information.

(Operation) Next, the operation of the radar apparatus of the present invention configured as described above will be described.

In the radar apparatus according to the present invention, the launch timing of the search beam and the tracking beam is scheduled so that the launch timing of the fixed number of search beams and the launch timing of one tracking beam alternate, and the tracking beam is assigned to the new target. At this time, a tracking beam that is at least one from the already used tracking beams is specified. That is, a spare tracking beam is secured in advance.

As a result, when a radar response cannot be obtained from the expected target, the tracking beam specified for the target can be changed to a spare tracking beam, and the tracking beam can be emitted again within one radar scan.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the radar apparatus of the present invention, as the firing timing of the search beam and tracking beams, for example, as shown in FIG. 2, a firing timing of the firing timing and one of the tracking beams T _i of a certain number of search beam S is alternately As shown in FIG. 3, for example, a beam number changing circuit 3 and a beam number management circuit 4 are added as a configuration of the target processing unit. The function has been added.

In other words, the tracking processing circuit 11a outputs information on the current target position and speed, the track number, and the target as in the case of the conventional tracking processing circuit 11b. Other information includes "whether or not to emit a tracking beam again for the same target".

Upon receiving the output of the tracking processing circuit 11a, the beam number change circuit 3 requests and obtains the beam number management information a from the beam number management circuit 4, and specifies and changes the beam number as follows, The result is output to the beam number management circuit 4 as beam number change information b.

For example, if the present radar system is capable of target tracking up to 10 aircraft, n = 10 becomes the second view, the tracking beam is a ten to T ₁ through T _10. FIG. 4 shows only the ten tracking beams extracted, and it is assumed that a series of numbers (beam numbers) are assigned in order from the leading side in one radar scan.

When the output of the tracking processing circuit 11a includes "start tracking for a new target", an ideal beam number and a track number are designated by referring to the obtained beam number management information a. That is, designation is made so as to be evenly distributed within one radar scan. For example, if the tracking of one aircraft has already been performed with the tracking beam of the beam number “1”, when adding the tracking of another aircraft, the beam number “6” is designated instead of the beam number “2”. . In addition, when beam numbers “1” and “6” are in use and three more aircraft are to be tracked to track a total of five aircraft, every other beam number (1 in FIG. 4) , 3,5,7,9).

Then, when the output of the tracking processing circuit 11a indicates that "there is no radar response, so the beam is turned again",
A beam number to which a beam can be directed again before the next radar scan is determined with reference to the obtained beam number management information a. For example, when the number of trackers is five, and tracking is performed with the beam numbers “1”, “3”, “5”, “7”, and “9” as shown in FIG. When there is no radar response for the target of “3”, an unused beam number “6” is designated, and for the target of beam number “5”, a beam number “8” is designated. Thus, even when there is no radar response, it is possible to aim the beam again and supplement the tracking information before the next radar scan.

When the output of the tracking processing circuit 11a is "continue", the specified beam number is checked with reference to the obtained beam number management information a.

The beam number management circuit 4 manages a combination of a track number of a tracked target and a designated beam number. The beam number management circuit 4 outputs the beam number management information a in response to a request. The management content is updated according to the change information b, so that the latest beam number management information a can always be output.

Further, the beam number changing circuit 3 calculates the difference between the time at which the beam is directed this time and the time at which the beam is directed next time after the above-described designation / change of the beam number, and calculates the difference between the value and the current smoothed position and speed. Tracking information c including information, a beam number, and a track number, and forming the same in a predicted position calculating circuit 2
Output to The tracking information c is the same as the output content of the conventional tracking processing circuit 11b except for the "value". That is,
The “value” is the same as the period of one radar scan in the conventional radar apparatus, and does not need to be calculated. However, in the radar apparatus of the present invention, since the beam is re-designated, the time is short in one radar scan. This may be calculated by the beam number changing circuit 3.

Therefore, the predicted position calculation circuit 2 predicts the position where the target will reach by the same procedure as in the related art, and outputs the position information, the beam number, the track number, and the like to the beam control unit and the track data management circuit 12. The calculation of the predicted position is performed using, for example, the following equations (1) to (3).

x = x ₀ + V _x · t (1) y = y ₀ + V _y · t (2) z = z ₀ + V _z · t (3) where x, y, and z represent the next time The three-dimensional predicted position to direct the beam, x ₀ , y ₀ , z ₀ is the three-dimensional position when the current beam is directed, and V _x , V _y , V _z is the three-dimensional position when the current beam is directed. Target speed, t is the time from this time to turn on the next beam,
That is, the “its value”.

(Effect of the Invention) As described above, according to the radar apparatus of the present invention,
The launch timing of the search beam and the tracking beam is scheduled so that the launch timing of a fixed number of search beams and the launch timing of one tracking beam are alternated. When a tracking beam is assigned to a new target, the existing tracking beam is used. Is specified at least one tracking beam. That is, since a spare tracking beam is secured in advance, when a radar response cannot be obtained from an expected target, the tracking beam specified for the target is changed to a spare tracking beam, and the target beam is changed within one radar scan. In this case, the tracking information can be supplemented by emitting the tracking beam again, and there is an effect that it is possible to reliably continue the tracking with respect to the target that is difficult to obtain a response.

Especially, for the target where the difference between the predicted position and the actual position becomes large in proportion to the elapsed time due to the large acceleration, and for the target where the reflection area is small and the radar response is difficult to obtain, the same reliable tracking as other targets Therefore, the effect is great.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between a search beam and a tracking beam within the coverage area of a radar device to which the present invention is applied, FIG. 2 is a diagram showing an example of a beam emission timing schedule in the radar device of the present invention, and FIG. FIG. 4 is a block diagram of a target processing unit in the radar apparatus of the present invention, FIG. 4 is an explanatory view of a method of specifying a tracking beam, FIG. 5 is a view showing an example of a launch timing schedule in a conventional radar apparatus, and FIG. FIG. 3 is a configuration block diagram of a target processing unit in the radar device of FIG. 1 target tracking circuit 2 predicted position calculation circuit 3
Beam number changing circuit, 4 ... Beam number management circuit, 11a
…… Tracking processing circuit, 12 …… Track data management circuit.

Claims (1)

(57) [Claims] 1. A radar apparatus for scanning a whole covered area with a search beam in one radar scan and tracking a plurality of detected targets with a corresponding tracking beam; firing timing of a certain number of search beams in one radar scan And the launch timing of one tracking beam are alternately defined; referring to the obtained beam number management information, at least one of the launch timings of the tracking beam already used as the tracking beam for the new target is set. Specifying the tracking beam for the firing timing, and specifying and changing the unused tracking beam for the firing timing after the firing timing of the tracking beam specified for the target when the radar response cannot be obtained from the expected target Means for outputting beam number change information relating to the tracked beam thus obtained;
The radar device manages a combination of a track number of a target tracked by the radar device and a tracking beam number designated to the target, and outputs the beam number management information in response to a request. Means for updating the management content in accordance with the number change information.