JP3065043B2 - Conical scan tracking method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target tracking device, and more particularly, to a control device mounted on a flying object such as a missile, for performing a conical scan of a gimbal while tracking a target.

[0002]

2. Description of the Related Art A target tracking device for mounting a flying object includes an image sensor for capturing a target and a gimbal mechanism for mounting the image sensor and spatially stabilizing the object without being affected by the movement of the flying object. A gimbal mechanism is driven by an induction signal based on the target angle and an error angle of the image sensor, and the gimbal mechanism is swung in two axial directions to track the target.

FIG. 4 is a block diagram of a tracking control loop in a conventional missile guidance system. The tracking loop system includes a gimbal control unit 1 having angular velocity feedback, and an integral element indicating a physical phenomenon from angular velocity to angle. 2, a target direction angle 3, a calculation delay 4 of the signal processing unit, a tracking gain 5, and a guidance signal 6 to be output to the flying object.

The gimbal control unit 1 includes an angular velocity loop gain 7, a calculation delay 8 of the gimbal control unit 1, a torque motor gain 9, friction 10 such as mechanical contacts and wiring, a gimbal inertia moment 11, a viscous resistance, a spring torque 12, Angular velocity detector 13 for detecting gimbal angular velocity
It is composed of

[0005] The calculation delay 4 of the signal processing unit occurs when the guidance signal 6 is calculated based on the target direction angle and the error angle of the image sensor. Guidance signal 6 for guidance control of a flying object
Is also supplied to the gimbal control unit 1 and the gimbal control unit 1
The gimbal mechanism is swung in two axial directions to track the target.

Some of the current missile guidance devices include a conical scan of a gimbal mechanism to expand a search field of view before tracking a target, and stop a conical scan and operate a tracking control loop after a target is detected. In some cases, the probability of target detection is increased.

[0007]

At present, this conical scan is performed only at the time of searching for a target. However, the conical scan is performed while capturing and tracking a certain target. It is conceivable to increase the number of candidates to confirm whether an object is a true goal. However, if conical scanning is performed during target tracking, a signal component that must not be output to the guidance signal output to the flying object is generated, and target tracking becomes unstable.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide means for preventing a gimbal from conical scanning during target tracking without affecting an induced signal output to a flying object. .

[0009]

SUMMARY OF THE INVENTION The present invention relates to a tracking device for mounting a flying object having an image sensor mounted on a gimbal mechanism, which performs conical scanning during target tracking and controls a flying object during tracking. The cancellation signal that simulates the response of the gimbal by conical scan is added to the guidance signal, thereby suppressing the influence on the guidance signal output to the flying object even if the gimbal is conical scanned during target tracking. It is characterized by doing.

If a conical scan is performed during tracking, the center of the visual field of the image sensor rotates so as to be concentric with the target direction axis, so that an undesirable signal is added to the guidance signal in the tracking loop. However, according to the present invention, the output of the canceling element simulating the response of the gimbal is subtracted from the induced signal to cancel the effect of the conical scan, so that the conical signal to the induced signal is eliminated. The effect of scanning can be reduced.

[0011]

FIG. 1 is a block diagram showing an embodiment of the present invention. The tracking loop system basically includes a gimbal control unit 1 having angular velocity feedback, an integral element 2 indicating a physical phenomenon from angular velocity to angle, a target direction angle 3, and a calculation delay 4 of a signal processing unit, similarly to the conventional example. , A tracking gain 5, and a guidance signal 6 to be output to the flying object. Further, the gimbal control unit 1 includes an angular velocity loop gain 7, a calculation delay 8 of the gimbal control unit 1, a motor gain 9, a mechanical contact, friction 10 such as wiring, a gimbal inertia moment 11, a viscous resistance, and a spring torque 1.
2. It comprises an angular velocity detector 13 for detecting the angular velocity of the gimbal.

The present invention includes a canceling element 15 simulating the response of a gimbal, and transmits a conical scan command signal 4
There is a means for adding (subtracting) immediately before the addition point of the angular velocity feedback via the canceling element 15. The gimbal conical scan command 14 is given as an angular velocity in this embodiment.

FIG. 2 is a block diagram showing a configuration of the canceling element 15 simulating a gimbal response. The canceling element 15 simulates the open loop characteristics of the system, and includes a model 16 that approximates the gimbal angular velocity feedback loop, an integrating element 17, a gain 18 when the target angle is 0 °, and a calculation delay of the signal processing unit. 19, tracking gain 20
It is composed of

FIG. 3 is a conceptual diagram when the image sensor 21 is conical scanned during tracking. As shown in FIG. 3, the conical scan during tracking is to rotate the image sensor 21 so that the center of the field of view of the image sensor 21 is concentric with respect to the target direction axis 22. An undesired signal for the flying object is added to the signal 6. Therefore, according to the present invention, the output of the cancellation element 15 simulating the response of the gimbal is subtracted immediately after the tracking gain 5 so as to cancel the effect of the conical scan. This makes it possible to reduce the influence of the conical scan on the guide signal 6.

Next, the operation of the present invention will be described with reference to FIG. When a conical scan command 14 for conical scanning the gimbal is added immediately before the point of addition of the angular velocity feedback during the target tracking, the sum of the conical scan command 14 and the guidance signal 6 becomes the gimbal control unit 1.
The gimbal performs a conical scan centering on the tracking target position. With this input, a signal corresponding to the movement of the gimbal is generated in the guidance signal 6.

On the other hand, when the conical scan command 14 is input to the canceling element 15 simulating the response of the gimbal shown in FIG.
The same signal as the output when the conical scan command 14 is input to the tracking loop block including the integration element 2, the signal processing unit 4, and the tracking gain 5 is obtained. By subtracting this signal from its output immediately after the tracking gain 5 on the tracking loop system, the signal component generated by the conical scan command 14 can be canceled from the induction signal 6.

In the above-described embodiment, the conical scan command 14 is given as an angular velocity, but it is also possible to give it as an angle or a motor torque.
In that case, the input position of the scan command 14 is different,
The configuration of the cancellation element 15 is also different from the configuration of FIG. 2, but is similar in that a signal corresponding to the movement of the gimbal in accordance with the conical scan command is subtracted from the induced signal.

[0018]

According to the present invention, it is possible to extend the sensing range of the image sensor by performing a conical scan and moving the image sensor even during tracking.
The field of view of the image sensor can be expanded equivalently.

In order to enhance the accuracy of the missile tracking device, conflicting performances of a wide field of view and high resolution are required. According to the present invention, the field of view lost by increasing the image resolution is conical scan. Therefore, the image resolution of the image sensor can be further increased, and precise guidance can be performed.

Further, according to the present invention, the field of view is expanded as compared with the case where no scanning is performed, so that the number of target candidates in the expanded field of view increases. Therefore, as the population of target candidates to be image-processed increases, the probability of capturing the real target increases, and as a result, the probability that the tracked target is the real target can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a specific example of an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing the operation of the present invention.

FIG. 4 is a block diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gimbal control part 2, 17 Integral element 3 Target direction angle 4, 19 Signal processing part 5, 20 Tracking gain 6 Guidance signal 7 Angular velocity loop gain 8 Calculation delay 9 Torque motor gain 10 Friction 11 Gimbal inertia moment 12 Viscous resistance spring torque 13 Angular velocity detector 14 Conical scan command 15 Negative element 16 Gimbal response simulation element 18 Gain when target angle is 0 degree 21 Image sensor 22 Target direction axis 23 Target

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01S 13/00-13/95 F41G ⁷ /20-7/28

Claims (3)

(57) [Claims] An image sensor is mounted on a gimbal mechanism, and a guidance signal generated based on a target angle and an error angle of the gimbal mechanism is fed back to the gimbal mechanism. A conical scan tracking method, comprising: inputting a conical scan signal to the gimbal mechanism and subtracting a signal for canceling the effect of the conical scan from the guide signal. 2. The signal for canceling the effect of the conical scan is a signal simulating a gimbal response from the conical scan signal input point of the gimbal mechanism to the guidance signal output point with respect to the conical scan signal. The conical scan tracking method according to claim 1, wherein: 3. A target tracking device for mounting a flying object, wherein an image sensor is mounted on a gimbal mechanism, and a guidance signal generated based on a target angle and an error angle of the gimbal mechanism is fed back to the gimbal mechanism. A conical scan commanding means for inputting a conical scan signal to the gimbal mechanism, and a signal simulating a gimbal response from the conical scan signal input point of the gimbal mechanism to the guidance signal output point, which inputs the conical scan signal. A conical scan tracking device, comprising: a canceling element for performing the canceling; and means for subtracting an output of the canceling element from the guide signal.