JP3111218B2 - Target tracking device - 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 mounted on a flying object such as an aircraft for capturing and tracking a target.

[0002]

2. Description of the Related Art Conventionally, as a target tracking device mounted on an aircraft, a method of obtaining an infrared image of a target with an infrared imaging camera and tracking the target with positional information on the image is used. However, in this case,
When the temperature difference between the target and the background is small and the temperature distribution in the background is large, it is difficult to distinguish the target from the background, and the target cannot be detected stably.

[0003]

As described above, in the conventional target tracking device, the temperature difference between the target and the background is small.
When the temperature distribution in the background is large, there is a problem that the target may not be detected stably.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a target tracking device that stably detects and tracks a target.

[0004]

Means for Solving the Problems To solve the above problems, the present invention is configured as follows. (1) A pulse laser device that emits a laser beam, an imaging device that has sensitivity in the wavelength range of the laser beam, and the directional directions of the pulse laser device and the imaging device are matched with each other. A pointing device that appropriately directs the light , a background distance information obtaining unit that obtains distance information to a background in a direction in which the laser beam is directed at the time of imaging by the imaging device, and based on the background distance information obtained by the unit. A photosensitive timing control means for controlling the exposure timing of the imaging device to remove an echo component from the background so that only a target echo is obtained; and extracting a target image from an imaging signal obtained by the imaging device, and Signal processing means for generating a pointing control signal for directing the laser beam to the laser beam and sending the generated signal to the pointing device.

(2) In the configuration of (1), the background distance information acquisition means starts counting at the laser beam transmission timing with the laser receiver for receiving the echo of the laser beam, and And a counter for outputting a count value of the obtained echo reception timing as distance information.

(3) In the configuration of (1), the height of the altimeter
Flying based on degree information and attitude information of the inertial navigation system
When the flying object is mounted, the background distance information acquisition means
Angle in directional control signals obtained by the aircraft attitude information and the signal processing means of an advanced information and inertial navigation system of the altimeter
It is configured to include a calculation circuit that calculates background distance information from the information.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a basic configuration of a target tracking device according to the present invention. In FIG. 1, 1
Is a pulse laser device that emits a laser beam, and 2 is an imaging device that has sensitivity in the wavelength range of the laser beam. These devices 1 and 2 are fixed so that the directivity directions are the same as each other. It is attached to such a pointing device 3.

In the pointing device 3, a platform 32 is rotatably arranged on a base 31.
By rotatably mounting the pulse laser device 1 and the imaging device 2 between the pair of arms, the pulse laser device 1 and the imaging device 2 can be freely pointed within the hemisphere according to the pointing control signal. It was made.

On the other hand, the background distance information obtaining section 4 obtains distance information to the background (ground, sea surface, etc.) in the directional direction of the pulse laser device 1, and the obtained distance information is used as the exposure timing control section 5. Sent to

The exposure timing control unit 5 adjusts the exposure timing of the imaging device 2 based on the background distance information from the background distance information acquisition unit 4 so that only the target echo is obtained by removing the echo component from the background. To control.

The output of the imaging device 2 is supplied to a signal processing unit 6. The signal processing unit 6 extracts a target image by removing a clutter component from an imaging signal, and generates a pointing control signal for directing a laser beam to the center of the target image. The pointing control signal is sent to the pointing device 3. .

The background distance information acquiring section 4 is, for example, as shown in FIG.
As shown in (1), it is configured using a laser receiver 41 and a counter 42. The laser receiver 41 is mounted on the pulse laser device 1 so that the directional directions are the same, and outputs an echo reception timing signal when receiving an echo of a laser beam. The echo reception timing signal is supplied to the counter 42 together with the laser beam emission timing signal obtained by the pulse laser device 1.

The counter 42 starts counting clocks from the laser beam emission timing, and notifies the photosensitive timing control unit 5 of the count value as background distance information at each laser beam reception timing.

The operation of the above configuration will be described with reference to FIGS. FIG. 4 shows a situation in which the present apparatus is used. A indicates the present apparatus, B indicates a target helicopter, and C indicates a mountain serving as a background. Now, assuming that the laser beam emitted from the pulse laser device 1 of the device A is directed to the helicopter B, an echo from the mountain C in addition to the echo from the helicopter B is also incident on the imaging device 2.

At this time, the laser receiver 41 receives the echo from the helicopter B and the echo from the mountain C, and outputs a timing signal at each reception timing. FIG. 5 shows how the reflected light intensity changes at this time.

The counter 42 starts counting from the timing of emitting the laser beam from the pulse laser device 1,
Each time an echo reception timing signal is input from the laser receiver 41, the count value is sent to the exposure timing control unit 5.

The exposure timing control unit 5 regards the minimum value of the input count values as an echo from the target and is effective.
The subsequent count value is regarded as an echo from the background and ignored, and the exposure timing of the imaging device 2 is controlled so that the exposure is performed only during the period in which the echo from the target is received.

That is, when detecting the helicopter B in flight under the situation shown in FIG. 4, if the distance to the background is known, the speed c of light is known (about 3 × 10 8 m /
Therefore, if the distance to the background is r [km], the time τ [s] from emitting the laser beam to receiving the reflected light can be calculated by the following equation. τ = 2 · r / c In the case of the configuration shown in FIG. 3, in order to extract the distance to the background (mountain or the like), the output signal from the laser receiver 41 is output as shown in FIG. Focusing on the fact that the timing differs from the echo from the background, for example, the time from the time 0 [s] to the second pulse detected may be measured by a counter.

In the situation shown in FIG. 4, if the irradiation timing of the laser beam is time 0 [s], for example, the imaging device is kept in the photosensitive state from time 0 [s] to τ [s]. , Τ [s] or more, by controlling the exposure timing of the imaging device so as not to be exposed to light, the reflected light from the background can be prevented from being imaged.

For this reason, on the imaging screen of the imaging device 2, the background mountain C is not imaged, but only the echo from the target helicopter B is imaged. Therefore, in the signal processing unit 6, since noise from the background is suppressed, the target image can be reliably extracted, and the laser beam can be continuously applied to the helicopter B through the directing device 3. become.

Therefore, the target tracking device having the above-described configuration stably detects and tracks the target even when the temperature difference between the target and the background is small and the temperature distribution in the background is large as compared with the conventional target tracking device. be able to.

FIG. 6 shows the configuration of another embodiment of the target tracking device according to the present invention. However, in FIG. 6, the same parts as those in FIG. 3 are denoted by the same reference numerals, and different parts will be described here.

The features of this target tracking device are as follows:
As the configuration of the above-described background distance information acquisition unit 4, the aircraft attitude angle information and altitude information obtained by the inertial navigation device 7 and the altimeter 8 included in the machine equipped with this device, the laser beam directional information obtained by the pointing device 3, It is provided with a background distance calculation circuit 43 for calculating a background distance from the target tracking information obtained by the signal processing unit 6.

The method of extracting the distance to the background in this configuration will be described below with reference to FIG. In this method, the distance is calculated based on the assumption that the ground surface is flat and the sea level is constant. FIG. 7 shows a vertical plane including the laser irradiation direction. In FIG. 7, D represents an aircraft on which the apparatus is mounted, and E represents a target helicopter.

Based on the above assumption, the distance to the background (r)
Is the altitude (h) obtained from the altimeter 8, the inertial navigation device 7
And the laser beam irradiation angle (α) obtained by the pointing device 3 can be calculated by the following equation. Here, α and β are angles in the vertical plane. r = h / sin (β + α) Thus, even if no echo of the laser beam is received,
Since altitude information and body attitude angle information, the distance from the laser beam irradiation angle to the background can be measured, noise from the background can be suppressed, as in the case of the previous configuration.
The target can be detected and tracked stably.

[0026]

As described above, according to the present invention, it is possible to provide a target tracking device for stably detecting and tracking a target.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing an external configuration of the target tracking device in the embodiment.

FIG. 3 is a block diagram showing a specific configuration of a background distance information acquisition unit of the embodiment.

FIG. 4 is a diagram showing a situation in which the target tracking device according to the present invention is used.

FIG. 5 is a timing chart for explaining the operation of the laser receiver in the situation shown in FIG.

FIG. 6 is a block diagram illustrating another specific configuration of the background distance information acquisition unit according to the embodiment.

FIG. 7 is a diagram for explaining a background distance calculation method in the case of the configuration shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pulse laser device 2 ... Imaging device 3 ... Direction device 31 ... Base 32 ... Platform 4 ... Background distance information acquisition unit 41 ... Laser receiver 42 ... Counter 43 ... Background distance calculation circuit 5 ... Sensing timing control unit 6 ... Signal Processing unit 7: Inertial navigation system 8: Altimeter

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yoshiyuki Fukuyama 2-22-17-32 Higashiyama, Meguro-ku, Tokyo (72) Inventor Yuichiro Goto 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki City, Kanagawa Prefecture Inside the plant (72) Inventor Masazumi Oshita 1 Komukai Toshiba-cho, Koyuki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Komukai plant (56) References JP-A-58-175800 (JP, A) JP-A-58- 19572 (JP, A) JP-A-3-24684 (JP, A) JP-A-58-147668 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S 7/48-7 / 51 G01S 17/00-17/95 G01S 3/782

Claims (3)

(57) [Claims] 1. A pulse laser device for emitting a laser beam, an imaging device having sensitivity in a wavelength range of the laser beam, and the directional directions of the pulse laser device and the imaging device are matched with each other. A pointing device that appropriately directs according to the following; a background distance information obtaining unit that obtains distance information to a background in a pointing direction of the laser beam at the time of imaging by the imaging device; based on background distance information obtained by the unit. Controlling the exposure timing of the imaging device, removing the echo component from the background so that only the target echo is obtained, and extracting the target image from the imaging signal obtained by the imaging device, Signal processing means for generating a pointing control signal for directing the laser beam to the center thereof and sending the generated signal to the pointing device. Target tracking device. 2. The apparatus according to claim 1, wherein said background distance information acquisition means includes a laser receiver for receiving an echo of said laser beam, a count being started at said laser beam transmission timing, and a count value of an echo reception timing obtained by said laser receiver. The target tracking device according to claim 1, further comprising: a counter that outputs the distance information as distance information. 3. The altitude information of the altimeter and the body of the inertial navigation device.
During projectile mounted to fly based on the attitude information, the background distance information obtaining means, from the angle information in the directivity control signal obtained by the aircraft attitude information and the signal processing means of an advanced information and inertial navigation system of the altimeter The target tracking device according to claim 1, further comprising a calculation circuit that calculates background distance information.