JPH03152490A - Controlling apparatus for direction of laser beam - Google Patents

Abstract

PURPOSE:To control the direction of laser beams with high accuracy by automatically correcting the optical axis of the laser beams and automatically correcting the positional displacement of a target. CONSTITUTION:A gimbal part 11 adds scanning motion to a sending telescope 2 and a receiving telescope 1. The telescope 2 sends laser beams of a laser apparatus 13 to the scanning space, and the telescope 1 guides the receiving light to a dichroism beam splitter 3. The receiving light in the visible range is supplied to a pickup camera 5 which in turn searches for a flying object in the scanning space. After the flying object is found, the camera 5 continues to supply the positional information to a target tracing circuit 12. The circuit 12 generates and supplies a target tracing signal to the gimbal part 11. Moreover, the components of the receiving light outside the visible range are guided to a 4-quadrant photodetector 10. The detector 10 having a narrow visual field supplies the positional information of the flying object in the quadrant area to an angular error operating circuit 21. Then, the circuit 21 operates the angular error of the transmitted laser beams to the flying object. Since a driving circuit 22 and an automatic mirror gimbal 7 drives a reflecting mirror 6 so that the angular error becomes zero, the direction of the laser beams can be corrected with good accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser beam direction control device, and in particular, a device for controlling the position of a flying object or communicating with a flying object by using a laser beam as a medium between a ground device and a flying object. The present invention relates to a laser beam direction control device that controls the direction of a laser beam emitted from a ground device so as to track a flying object.

[Conventional technology]

Conventionally, in this type of laser beam direction control device, the entire ground device consists of a high-field camera device that transmits and receives the laser beam, a laser device that generates the laser beam to be transmitted, and a tracking device for the flying object. It is mounted on a gimbal mechanism that can control the spatial position, and in the initial state, it searches the tracking target space with a fixed scanning pattern and detects the reflected light from the opponent's flying object or the laser response light emitted from the flying object. Capture. After capture, the laser beam is irradiated while controlling the direction so as to track the reflected light or response light from the flying object.

In order to control the direction of the laser beam, a positional deviation signal between the irradiated beam and the received beam obtained through laser reflection or a position detector of the light source is converted into a directivity angle of the laser beam. The direction of the laser beam was controlled so as to directly face the flying object by driving and controlling an internal reflecting mirror that was interposed in the light transmission path and formed a portion of the light transmission path.

The above-mentioned internal reflecting mirror usually has two reflecting mirrors disposed in the optical path to change the optical path in the X direction and the Y direction, respectively, to provide the above-mentioned directivity angle.

[Problem to be solved by the invention]

When the relative speed to the flying object is high or when the distance is far, it is necessary to control the direction of the laser beam with high precision in order to track the flying object with high precision.

The above-mentioned conventional laser beam direction control device uses a tracking signal obtained from a flying object as a laser beam direction control signal. Therefore, the output beam direction of the laser device changes and the angle of the internal reflector that controls the laser beam direction changes. Therefore, there is a drawback that it is not possible to accurately control the direction of the laser beam in the direction of the detected laser light source.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a laser beam direction formal value that can compensate for variations in the output beam direction of a laser device and angular variations of an internal reflector.

[Means to solve the problem]

The device of the present invention is a laser beam direction control device that directs the transmitted laser beam toward the flying object while receiving reflected light or response light from the transmitted laser beam that is sent toward the flying object, and is equipped with a light transmitting/receiving system and a tracking system. a first tracking means that scans a space to be tracked of the flying object by the light transmitting/receiving system in a predetermined scanning pattern and, after capturing the flying object, causes the light transmitting/receiving system and the tracking system to track the captured flying object; Continuously and automatically controlling the pointing direction of the sending laser beam so as to correct the positional displacement of the flying pair between sending the sending laser beam and receiving the reflected light or response light by the light receiving system, and in the sending and receiving system. Laser beam optical axis maintenance that detects fluctuations in the optical axis of the emitted laser beam and automatically compensates for the fluctuations in the second tracking means that corrects tracking of the flying object while automatically correcting optical axis fluctuations. and means.

In addition, the device of the invention matches the transmitting magnification and the receiving magnification, transmits and receives a laser beam using a transmitting telescope and a receiving telescope that are arranged adjacently in parallel, and uses one double-sided reflecting mirror common to the transmitting and receiving system. Arranged so that spatial position can be controlled,
and the second tracking means configured to automatically correct the displacement of the flying object including the angular variation of the double-sided reflecting mirror while acquiring the displacement of the flying object with a four-quadrant photodetector. .

In addition, the device of the present invention has a deflection prism whose output angle can be changed in the laser beam transmission path, extracts a part of the laser beam through a partially transmissive mirror and a corner reflector, and changes its optical axis. The laser beam optical axis maintaining means is configured to detect the polarization prism with a four-quadrant photodetector and drive the deflection prism so that optical axis fluctuation becomes zero.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a laser beam direction control device of the present invention.

In the embodiment shown in FIG. 1, a receiving telescope 1 and a transmitting telescope 2 having the same receiving magnification and transmitting magnification, which are arranged parallel to each other and adjacent to each other, form the first tracking means.
A dichroic beam splitter 3 that passes light in the visible region and reflects light in other regions, an imaging lens 4, and an imaging camera that images a flying object that enters through the imaging lens 4 and outputs its position information. 5, and target tracking in which the transmitting/receiving telescope #11 and the receiving telescope 2 are directed toward the flying object based on the positional information of the flying object output from the imaging camera 5 so as to make the positional displacement of the flying object zero. It is equipped with a target tracking circuit 12 that outputs a signal, a control program, a light transmitting/receiving system, and a tracking system. a gimbal unit 11 that provides a scanning movement that scans regularly and continuously in a predetermined scanning pattern, and after capturing a flying object by this scanning movement, provides a tracking movement based on a target tracking signal provided from a target tracking circuit 12; It has a laser device 13 that generates laser light and a partially transmissive mirror 14.

In addition, as elements forming the second tracking means, the receiving telescope 1, the transmitting telescope 2, the dichroic beam splitter 3, the double-sided reflecting mirror 6, and the double-sided reflecting mirror 6 are stopped spatially with two degrees of freedom. and an automatic mirror gimbal 7 whose stop position can be controlled by a drive signal received from the outside, an interference filter 8 that blocks unnecessary components such as background light other than the transmitted laser beam, a condensing lens 9, and a condensing lens 9. A first four-quadrant photodetector 10 that detects the position of a supplementary flying object that receives light through one of the four-quadrant detection areas and outputs the position information, and an output of the first four-quadrant photodetector 10. Based on the location information,
a first angular error calculation circuit 21 that calculates the displacement of the captured flying object from the direction of the emitted laser beam, that is, the angular error;
A first drive circuit 2 that outputs a drive signal that causes the automatic mirror gimbal 7 to set the position of the double-sided reflector 6 so that the angular error output from the first angular error calculation circuit 21 is zero.
2, a laser device 13, and a partially transmissive mirror 14.

Further, the laser beam optical axis maintaining means is formed by combining the laser device 13 and two prisms each having a wedge-shaped cross section, and by rotating one prism with respect to the other prism, the rotation angle is changed. The beam passes through a deflection prism 20 whose output angle is made variable correspondingly, a partially transmissive mirror 14, a corner reflector 15, and a partially transmissive mirror 14,
A condenser lens 2 that focuses the laser beam that is totally reflected by the conner reflector 15 and then partially reflected again by the transmissive mirror 14.
3, a second quadrant detector 16 that receives the output light of the condenser lens 23 and outputs its position information, and a second quadrant detector 1
a second angular error calculation circuit 17 that calculates the angular error from the initial state of the generated laser beam based on the position information outputted by 6; the deflection prism drive unit 19; and the output of the second angular error calculation circuit 17 The second driving circuit 18 generates a drive signal that drives the deflection prism 20 with the deflection prism drive unit 19 based on the angle error to make the angle error zero and maintain the optical axis.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

In the initial state, the gimbal unit 11 is driven regularly according to a predetermined scanning pattern, and the laser beam output from the laser device 13 is transmitted through a light transmission path formed by the deflection prism 20, the partially transmissive mirror 14, and the double-sided reflected light 6. The reflected light or response light from the target flying object is captured by the receiving telescope 1 and guided to the dichroic beam splitter 3.

Of the light received by the dichroic beam splitter 3, that in the visible light range is supplied to the imaging camera 5 via the imaging lens 4. The imaging camera 5 is held to have as wide a field of view as possible to easily capture the target, and while searching for the flying object while imaging the light received from the space scanned by the gimbal unit 11 in the visible range, The position information of the flying object is continuously supplied to the target tracking circuit 12. The target tracking circuit 1 learns from the position information of the flying object the displacement of the flying object between the time of irradiation with the sending laser beam and the time of light reception, corrects this displacement to zero, and directs the sending laser beam to the flying object. The gimbal section 1 generates a target tracking signal for tracking.
1, thus causing the receiving telescope 1 and the transmitting telescope 2 to always be directed to track the captured projectile.

The above-mentioned tracking operation is performed by the transmitting telescope 2 and the receiving telescope 1.
However, in order to direct the sharp emitted laser beam toward the captured flying object with high precision, the following correction tracking is required.

That is, among the received light guided by the dichroic beam splitter 3, wavelength components other than the visible light range are reflected and projected onto the double-sided reflecting mirror 6, and then reflected and supplied to the interference filter 8. The interference filter 8 eliminates background light, scattered light, and other unnecessary components, and focuses only the necessary wavelength components through the condensing lens 9.
The first four-quadrant photodetector 10 transmits the position information of the captured flying object detected in which quadrant of the four-quadrant detection area. and supplies it to the first angular error calculation circuit 21.

The light-receiving field of view of the first four-quadrant photodetector 10 described above is set to be as narrow as possible in order to increase the angular error detection sensitivity, and the captured flying object is detected while the imaging camera 5 is tracking the target. As much as possible.

The first angular error calculation circuit 21 calculates the angular error of the transmitted laser beam with respect to the captured flying object, and supplies this to the first drive circuit 22 . The first drive circuit 22 generates a drive signal to drive the double-sided reflector 6 as an internal reflector common to the light receiving and transmitting systems so as to make the provided angular error zero, and supplies it to the automatic mirror gimbal 7. do. In this way, the pointing direction of the sending laser beam emitted from the transmitting telescope 2 can always accurately correct and track the captured flying object.

In this way, by matching the receiving magnification of the receiving telescope 1 and the transmitting magnification of the transmitting telescope 2, and by using the automatic mirror gimbal that automatically corrects the positional displacement of the flying object to control the direction of the transmitted laser beam, it is possible to capture the flying object. The direction of the emitted laser beam can be automatically controlled and tracked by the body.

Further, the angle fluctuation of the double-sided reflecting mirror 6 is also included in the tracking correction described above and is automatically corrected.

Now, the fluctuation control of the output beam from the laser device 13 is performed as follows. Part of the laser beam is transmitted through the transmission mirror 14, the transmitted light is reflected by the corner reflector 15, and the transmitted light is reflected through the condenser lens 28. The 0th order is supplied to the second four-quadrant photodetector 16 and detects the beam focusing position.
outputting the angular error by the second angular error calculation circuit 17;
By controlling the deflection prism 20 by the second drive circuit 18 and the deflection prism drive unit 19, fluctuations in the laser beam are automatically corrected.

In this way, highly accurate tracking of the target becomes possible by automatically correcting optical axis fluctuations of the transmitted laser beam and angular fluctuations of the internal reflection mirror.

〔Effect of the invention〕

As explained above, according to the present invention, the positional displacement of the target is automatically corrected by introducing the automatic correction of the laser beam optical axis dedicated to the laser device and the automatic correction that is also used to control the positional displacement of the receiving light source and the pointing direction of the laser beam. By doing this, it is possible to automatically correct the optical axis fluctuations of the output beam of the laser device and the angular fluctuations of the internal reflector that controls the direction of the laser beam, making it possible to realize a laser beam direction control device that can control the laser beam direction with high precision. effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a laser beam direction control device according to the present invention. 1...Receiving telescope, 2...Transmitting telescope, 3...2
Chromatic beam splitter, 4...imaging lens, 5...
Imaging camera, 6... Double-sided reflector, 7... Automatic mirror gimbal, 8... Interference filter, 9... Condensing lens, 10... First four-quadrant photodetector, 11... - Gimbal section, 12... Target tracking circuit, 13... Laser device, 14... Partially transmissive mirror, 15... Corner reflector, 16... Second four-quadrant photodetector, 17 ...
Second angular error calculation circuit, 18... second drive circuit,
19... Deflection prism drive unit, 20... Deflection prism, 21... First angular error calculation circuit, 22... First drive circuit, 23... Condensing lens.

Claims (3)

[Claims] (1) A laser beam direction control device that directs the transmitted laser beam toward the flying object while receiving reflected light or response light from the transmitted laser beam, which is equipped with a light transmitting/receiving system and a tracking system. a first tracking means for scanning a body tracking target space with a predetermined scanning pattern by the light transmitting/receiving system and, after capturing the flying object, causing the light transmitting/receiving system and the tracking system to track the captured flying object; Continuously and automatically controlling the pointing direction of the sending laser beam so as to correct the positional displacement of the flying pair between sending the sending laser beam and receiving the reflected light or response light, and changing the optical axis in the light transmitting/receiving system. laser beam optical axis maintaining means that detects fluctuations in the optical axis of the emitted laser beam in the second tracking means and automatically compensates for the fluctuations in the optical axis of the emitted laser beam in the second tracking means that performs tracking correction of the flying object while automatically correcting the A laser beam direction control device comprising: (2) Match the transmitting magnification and receiving magnification, transmit and receive the laser beam with the transmitting and receiving telescopes arranged adjacently in parallel, and control the spatial position of one double-sided reflector common to the transmitting and receiving system. The second method is configured such that the displacement of the flying object is automatically corrected, including the angular fluctuation of the double-sided reflecting mirror, while the displacement of the flying object is acquired by a four-quadrant photodetector. A laser beam direction control device according to Claim (1), characterized in that it comprises a tracking means. (3) A deflection prism with a variable output angle is installed in the laser beam transmission path, a part of the laser beam is extracted through a partially transmissive mirror and a corner reflector, and the optical axis fluctuation is detected in four quadrants. The laser beam according to claim 1, further comprising: the laser beam optical axis maintaining means configured to detect the polarization prism with a device and drive the deflection prism so that optical axis fluctuation becomes zero. Directional control device.