Installation structure and precise assembling method of long-distance laser target tracking and ranging optical path

Abstract

The application relates to a mounting structure and a precise mounting method of a long-distance laser target tracking and ranging optical path, which are used for high-precision mounting of the laser emission direction of a space target tracking and ranging optical path, the optical path comprising three reflecting mirrors, and the deviation between the laser emission direction reflected by the three reflecting mirrors and the rotation angle of a rotating table during the oscillation of an azimuth axis and a pitch axis is required to be minimized. First, a collimator is used to lead the azimuth axis and the pitch axis to a plane mirror; second, the second reflecting mirror and the first reflecting mirror are mounted and adjusted through the mounting mode of a spacer and a fastening screw, the grinding amount of the spacer is calculated according to the image movement track of the collimator or the laser imaging point movement track in a measuring camera, and the spacer is ground based on the grinding amount, so that the purpose of high-precision mounting is achieved; third, the mounting system of the third reflecting mirror is built through visible light camera zero-point calibration and the measuring camera and an angle reflector, so that the mounting of the third reflecting mirror is realized; and finally, the spacer and the fastening screw are reinforced through epoxy glue, so that the mechanical performance of the optical path is ensured.

Description

Technical Field

[0001] This invention belongs to the field of optical path assembly and adjustment technology, specifically relating to the precision assembly and adjustment of an optical path for long-distance laser target tracking and ranging in space. Background Technology

[0002] Long-range laser tracking and ranging systems belong to the category of optoelectronic tracking and aiming systems, and their applications in the aerospace field have been increasing in recent years. These systems integrate the tracking turntable and the laser's output optical path, utilizing Coudre mirrors to ensure the laser's output direction aligns with the turntable's tracking direction. The assembly and adjustment of the Coudre optical path requires high precision, is complex, and time-consuming. For laser tracking and ranging systems used in space, in addition to achieving the required assembly and adjustment precision, it is also necessary to improve their mechanical resistance, meaning the assembly and adjustment precision must remain stable after experiencing vibration environments. Summary of the Invention

[0003] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a precise assembly and adjustment method for a long-range laser target tracking and ranging optical path, so that the laser radar has high resolution, high imaging frame rate, high measurement accuracy and long operating range.

[0004] The technical problem solved by this invention is: in a long-range laser tracking and ranging system, to achieve precise real-time alignment between the laser emission direction and the turntable axis, that is, when the turntable swings at a certain angle, the emitted laser beam also swings at the same angle. The laser emission direction is achieved through three reflectors, therefore the angles of the reflectors need to be precisely adjusted to ensure real-time alignment between the laser emission direction and the turntable axis.

[0005] The technical solution provided in this application is as follows:

[0006] An installation structure for a long-range laser target tracking and ranging optical path is disclosed. The long-range laser target tracking and ranging optical path includes a laser, a first reflector, a second reflector, a third reflector, and a multimode receiving optical system arranged sequentially along the optical path. The second reflector is connected to a turntable, which includes an elevation axis and an azimuth axis. The azimuth axis rotates around the axis of the elevation axis along with the elevation axis. The elevation axis rotates around its own axis. The elevation axis and the azimuth axis are provided with through holes along their own axial directions, and the through holes of the azimuth axis and the elevation axis are connected. The second reflector is fixedly connected inside the azimuth axis. The multimode receiving optical system is fixedly connected to the pitch axis; the third reflector is also fixedly connected to the multimode receiving optical system. The first, second, and third reflectors are all fixed by mounting brackets. The mounting brackets include a reflector mount, a reflector support, spacers, and screws. The first, second, or third reflector is glued to the reflector mount. Three spacers and three screws are provided. The three spacers are located between the reflector mount and the reflector support. The screws pass through the reflector mount and the spacers and are threaded to the reflector support, so that the reflector mount is fastened to the reflector support by the three spacers and screws. The angle of each first, second, or third reflector is adjusted by grinding the height of the three spacers.

[0007] The installation and adjustment method of the above-mentioned long-range laser target tracking and ranging optical path includes:

[0008] S1: Install a plane mirror leading out from the pitch axis at the light output end of the pitch axis;

[0009] S2: Install an azimuth axis lead-out plane mirror at the light incident end of the azimuth axis;

[0010] S3: After installing the pitch axis lead-out plane mirror and the azimuth axis lead-out plane mirror on the turntable, install and adjust the second reflecting mirror;

[0011] S4: Install and adjust the first reflecting mirror;

[0012] S5: Install and adjust the third reflecting mirror.

[0013] Furthermore, the installation of a pitch axis lead-out plane mirror at the light-emitting end of the pitch axis includes:

[0014] Place the turntable horizontally on the optical platform and fix the azimuth axis to ensure that the turntable can only rotate on the pitch axis.

[0015] Install a pitch axis lead-out plane mirror at the light output end of the pitch axis, and set up an autocollimator directly in front of the pitch axis lead-out plane mirror so that the autocollimator autocollimates the pitch axis lead-out plane mirror.

[0016] Continuously rotate the pitch axis of the turntable and adjust the orientation of the normal of the pitch axis-leading plane mirror until the diameter of the crosshair circle drawn by the autocollimator is within the required value, and fix the relative position of the pitch axis-leading plane mirror and the pitch axis.

[0017] Furthermore, the installation of the azimuth axis lead-out plane mirror at the incident end of the azimuth axis includes:

[0018] Raise the turntable as a whole, install the interface at the bottom of the azimuth axis to install the azimuth axis lead-out plane mirror;

[0019] A 45° reflector is fixedly installed directly below the azimuth axis of the turntable, and an autocollimator is set up so that the 45° reflector is within the field of view of the autocollimator, and the plane mirror drawn out by the autocollimator is autocollimated to the azimuth axis.

[0020] Rotate the azimuth axis of the turntable and adjust the direction of the normal of the azimuth axis-leading plane mirror until the diameter of the crosshair circle drawn by the autocollimator is within the required value. Fix the relative position of the azimuth axis-leading plane mirror and the azimuth axis.

[0021] Furthermore, the mounting and adjusting of the second reflector includes:

[0022] S31: Keep the positions of the autocollimator, 45° reflector, and turntable unchanged when the azimuth axis lead-out plane mirror is installed at the light incident end of the azimuth axis;

[0023] S32: Install the three support pillars, mirror mount, mirror bracket, and second mirror of the second reflector; lock the pitch axis of the turntable, rotate the azimuth axis of the turntable, and observe the diameter of the autocollimator's image return circle. If it is less than or equal to the required value, the second reflector installation and adjustment are complete; if it is greater than the required value, precisely install and adjust the second reflector until the diameter of the autocollimator's image return circle is less than or equal to the required value; lock the azimuth axis, rotate the pitch axis, and observe the diameter of the autocollimator's image return circle. If it is confirmed to be less than or equal to the required value, the second reflector installation and adjustment are complete.

[0024] Furthermore, the precision adjustment of the second reflecting mirror includes:

[0025] S321: Rotate the azimuth axis to different angles multiple times and record multiple autocollimator image return positions;

[0026] S322: Perform least-squares fitting on multiple autocollimator image positions to obtain the center coordinates and radius of the circle. The center coordinates are the target position for autocollimator image adjustment.

[0027] S323: Tighten or loosen each of the three screws in the mounting bracket of the second reflector in sequence, while simultaneously observing the direction of change of the image returned by the autocollimator, whether it is moving closer to or away from the target position, to determine the pads that need to be ground: when a screw is tightened and the image returns closer to the center, the height of the pad corresponding to that screw is ground, and the grinding amount is obtained through calculation; when a screw is loosened and the image returns closer to the center, the pads corresponding to the other two screws are ground, and the grinding amount is obtained through calculation.

[0028] S324: For a pad that needs to be ground, tighten the pad and record the change in the image angle on the autocollimator caused by tightening the pad. Calculate the grinding amount of the pad based on the change in the image angle, grind according to the grinding amount of the pad, and record the distance between the image of the autocollimator and the target position after grinding.

[0029] S325: If the distance between the image returned by the autocollimator in S324 and the target position does not meet the requirements, repeat S324 for the same pad until the distance between the image returned by the autocollimator and the target position meets the requirements, and then continue to grind the next pad that needs to be ground through S324.

[0030] Furthermore, the grinding amount Δl of a certain pad of the second reflector that needs grinding in the i-th grinding iteration. 2i The calculation formula is as follows:

[0031] Where, d 2i H represents the change in the image angle on the autocollimator caused by the i-th tightening adjustment of a certain shim of the second reflector; 2j The height of the support column.

[0032] Further, the mounting and adjusting of the first reflecting mirror includes:

[0033] A measuring camera is fixedly installed at the light output end of the pitch axis;

[0034] Install a center attenuator between the measuring camera and the pitch axis;

[0035] The first reflector is mounted on a support directly below the azimuth axis, and a laser is installed thereon. The light emitted by the laser is used as the incident light for the first reflector.

[0036] Keep the pitch axis of the turntable stationary, rotate the azimuth axis of the turntable, and adjust the thickness of the pads included in the mounting bracket of the first reflector until the change in the centroid position of the laser spot formed on the measuring camera is less than the required value, so that the screws included in the mounting bracket of the first reflector are fixed to the reflector bracket.

[0037] Furthermore, the installation and adjustment of the third reflecting mirror includes:

[0038] Install the third reflecting mirror together with the multimode receiving optical system. Set up the autocollimator in front of the secondary mirror of the multimode receiving optical system and the field of view of the visible light camera. Autocollimate the autocollimator with the outer end face of the secondary mirror. Adjust the attitude of the autocollimator to bring the image back to the zero point of the autocollimator. Then, turn on the visible light camera and make the crosshairs of the autocollimator image in the visible light camera. Record the position of the crosshairs in the measurement coordinate system of the visible light camera at this time. This position is the zero point of the visible light camera.

[0039] The measuring camera is placed in the light-emitting direction of the third reflecting mirror, and an attenuator is installed between the light-emitting direction of the third reflecting mirror and the measuring camera. Then, a corner reflector is placed in front of the autocollimator and the measuring camera, so that the crosshairs of the autocollimator are imaged in the measuring camera after passing through the corner reflector. Finally, the laser is powered on, so that the laser beam is reflected by the third reflecting mirror and attenuated by the attenuator before being imaged in the measuring camera. The position coordinates (X0, X0) of the image of the autocollimator crosshairs in the measuring camera are recorded. This position is the projection position of the zero point of the visible light camera in the measuring camera.

[0040] Adjust the three pads included in the mounting bracket of the third reflector until the deviation between the image of the autocollimator crosshair in the measuring camera and the laser imaging point is within the required value, so that the screws included in the mounting bracket of the third reflector are fixed to the reflector bracket.

[0041] Compared with the prior art, the present invention has at least the following beneficial effects:

[0042] (1) The present invention provides a calculation formula for the grinding amount of the shim during the assembly and adjustment of the reflector. Compared with the traditional assembly and adjustment method, it has a clear direction and can significantly improve the assembly and adjustment accuracy and efficiency.

[0043] (2) For the assembly and adjustment of the Kuder mirror (first mirror and second mirror), the main method is to rotate the azimuth axis for assembly and adjustment, and the rotation of the pitch axis is used as an auxiliary verification. This avoids the repeated assembly and adjustment process that requires considering both the azimuth axis and the pitch axis, and improves the assembly and adjustment efficiency.

[0044] (3) After the mirror is assembled and adjusted, the mounting surface of the mirror support structure is sealed with optical structural adhesive to increase the mechanical stability of the assembly and adjustment accuracy. Attached Figure Description

[0045] Figure 1 This is a flowchart of the assembly and adjustment process;

[0046] Figure 2 This is a schematic diagram of the reflector installation method;

[0047] Figure 3 Schematic diagram for adjusting the mirror leading out from the pitch axis of the turntable;

[0048] Figure 4Schematic diagram of the adjustment of the turntable azimuth axis lead-out mirror;

[0049] Figure 5 This is a schematic diagram of the installation and adjustment of the second reflecting mirror;

[0050] Figure 6 This is a schematic diagram of the image rewind adjustment process;

[0051] Figure 7 Adjust the optical path diagram for the first reflecting mirror;

[0052] Figure 8 A schematic diagram of zero-point calibration for a visible light camera;

[0053] Figure 9 A schematic diagram of the assembly and adjustment of the optical system's reflector;

[0054] Figure 10 This is a schematic diagram of the optical path.

[0055] Explanation of reference numerals: 1. Laser; 2. First reflector; 3. Second reflector; 4. Third reflector; 5. Multimode receiving optical system;

[0056] 51. Housing of multimode receiving optical system; 52. Secondary mirror; 53. Visible light camera;

[0057] 61. Azimuth axis; 611. Plane mirror derived from the azimuth axis; 62. Pitch axis; 621. Plane mirror derived from the pitch axis;

[0058] 71. Mirror bracket; 72. Mirror mount; 73. Support post; 74. Screw;

[0059] 81. Autocollimator; 82. 45° reflector; 83. Center attenuator; 84. Measuring camera; 85. Attenuator; 86. Corner reflector. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0061] A precision assembly and adjustment method for a long-range laser target tracking and ranging optical path, such as... Figure 10As shown, its optical path includes a laser 1, a first reflector 2, a second reflector 3, a third reflector 4, and a multimode receiving optical system 5 arranged sequentially along the optical path. The second reflector 3 is mounted on a turntable, which includes an elevation axis 62 and an azimuth axis 61. The azimuth axis 61 rotates around its axis along with the elevation axis 62; the elevation axis 62 rotates around its own axis; both the elevation axis 62 and the azimuth axis 61 have through holes along their own axes, and the through holes of the azimuth axis 61 and the elevation axis 62 are connected. The second reflector 3 is fixedly connected inside the azimuth axis. The multimode receiving optical system 5 is fixedly connected to the elevation axis 62; the third reflector 4 is fixedly connected to the multimode receiving optical system. The first reflector 2 is located at the laser output end and is used to deflect the laser output light into the azimuth axis of the turntable; the second reflector is located at the intersection of the azimuth axis and the pitch axis and is used to deflect the light from the azimuth axis into the pitch axis; the third reflector is used to deflect the output light from the pitch axis and make it parallel to the multimode receiving optical system.

[0062] The first reflector 2, the second reflector 3, and the third reflector 4 are all fixed by mounting brackets. Each of these is referred to as a reflector body. The mounting bracket includes a reflector base 72, a reflector support 71, spacers 73, and screws 74. The reflector bodies are glued to the reflector base. Three spacers and three screws are provided, each located between the reflector base and the reflector support. The screws pass through the reflector base and the spacers and are threaded onto the reflector support, thus securing the reflector base to the reflector support via the three spacers and screws. The angle of each reflector body (i.e., the first, second, or third reflector) is adjusted by grinding the height of the three spacers.

[0063] The multimode receiving optical system 5 includes a multimode receiving optical housing 51, a secondary mirror 52, and a visible light camera 53. The secondary mirror 52 and the visible light camera 53 are both fixedly connected to the multimode receiving optical housing 51.

[0064] This application discloses a precision assembly and adjustment method for a long-range laser target tracking and ranging optical path, including the assembly and adjustment process of the laser emission optical path, the tooling and equipment used for assembling and adjusting the three reflectors, the installation method and adjustment method of the reflectors, and details of the assembly and adjustment process.

[0065] The installation and adjustment sequence is as follows: First, use the lead-out plane mirror assembly to lead out the pitch axis and azimuth axis to the lead-out plane mirror; then, install and adjust the second reflector 3, the first reflector 2, and the third reflector 4 in sequence.

[0066] The assembly and adjustment process consists of 6 steps, such as... Figure 1 As shown, the specific assembly and adjustment process is as follows:

[0067] ①Preparation for assembly and adjustment

[0068] It includes a turntable, second reflector 3, first reflector 2, third reflector 4 and supporting structure in the laser emission optical path, 2 sets of autocollimators, 1 set each of corner reflector, measuring camera, and 45-degree tooling reflector, 2 sets of lead-out plane mirror assembly, optical structure, etc.

[0069] ② Adjusting the plane mirror derived from the pitch axis

[0070] like Figure 3 As shown, the specific steps for assembling and adjusting the plane mirror 621 extending from the pitch axis are as follows:

[0071] a. The turntable is placed horizontally on the optical platform, with the azimuth axis 61 fixed to ensure that the turntable can only rotate on the pitch axis 62.

[0072] b. Install an outgoing plane mirror assembly at the optical system end of the pitch axis 62. This outgoing plane mirror assembly includes a pitch axis outgoing plane mirror with an inner ring that transmits light (the central transmission area is not less than 8mm) and an outer ring that reflects light. The normal of this pitch axis outgoing plane mirror needs to be adjustable along both axes. Both surfaces of the pitch axis outgoing plane mirror are reflective and transparent.

[0073] c. Use the autocollimator 81 to assemble and adjust the elevation axis leading-out plane mirror 621. The autocollimator 81 is set up directly in front of the elevation axis leading-out plane mirror 621. Autocollimate the elevation axis leading-out plane mirror 621 by continuously rotating the elevation axis of the turntable and adjusting the orientation of the normal of the elevation axis leading-out plane mirror to ensure that the diameter of the crosshair circle drawn by the autocollimator is within 2″ (adjust the autocollimator to ensure that the autocollimated image is near X=0 and Y=0 to improve measurement accuracy).

[0074] ③ The azimuth axis is extended from the plane mirror 611 for installation and adjustment.

[0075] like Figure 4 As shown, the specific steps are as follows:

[0076] a. The turntable is raised by at least 200mm, and an interface is installed at the bottom of the azimuth axis 61 to install the azimuth axis lead-out plane mirror 611. Both surfaces of the azimuth axis lead-out plane mirror 611 are reflective and transparent.

[0077] b. A 45° reflector 82 is fixedly installed directly below the azimuth axis 61 of the turntable, and the 45° reflector 82 is within the field of view of the autocollimator 81.

[0078] c. Set up the autocollimator 81 and adjust the azimuth axis extension plane mirror 611. The autocollimator 81 is set up as follows: Figure 4 As shown, the plane mirror leading out from the azimuth axis is autocollimated. The azimuth axis of the turntable is rotated, and the direction of the normal of the plane mirror leading out from the azimuth axis is adjusted to ensure that the diameter of the crosshair circle drawn by the autocollimator is within 2″ (adjust the autocollimator to ensure that the autocollimated image is near X=0 and Y=0 to improve measurement accuracy).

[0079] d. After adjustment, keep the relative angles between the azimuth axis lead-out plane mirror 611 and the pitch axis lead-out plane mirror 621 and the turntable unchanged, and keep the positions of the autocollimator 81 and the 45° reflector 82 unchanged in this step, so as to install and adjust the second reflector 3.

[0080] ④ Second reflecting mirror 3 installation and adjustment

[0081] The goal of assembling the second reflector 3 (turntable reflector) is to make the azimuth axis 61 and the pitch axis 62 of the turntable form a reflected light path along the normal of the second reflector 3 (turntable reflector), that is, when light enters from one rotation axis, it exits from the other rotation axis after passing through the reflector.

[0082] The installation method of the second reflector is as follows: Figure 2 As shown, the second reflector is glued to the reflector mount, which is secured to the reflector bracket by three spacers and screws. The reflector bracket is fixed to the azimuth axis and moves with the azimuth axis but not with the pitch axis.

[0083] like Figure 5 As shown, keep the positions of the autocollimator 81, 45° reflector 82 and turntable unchanged when the azimuth axis plane mirror 611 is being adjusted, and install the reflector mount on the reflector bracket; lock the turntable pitch axis 62 in place, rotate the turntable azimuth axis 61, and adjust the thickness of the reflector mount pad so that the diameter of the crosshair circle of the autocollimator is within the required value; after adjustment, seal the screws with optical structural adhesive.

[0084] The thickness of the three shims is adjusted by grinding. The specific operation process is as follows:

[0085] a. Rotate the azimuth axis at different angles. The autocollimator's image return trajectory is an arc. Record the X and Y values ​​of the trajectory, recording at least 5 points. Perform least-squares fitting on the 5 recorded points to obtain the center coordinates and radius. The center position (i.e., the center coordinates) is the target position for autocollimator image return adjustment. Figure 6 As shown.

[0086] b. Tighten or loosen each of the three screws in turn, and at the same time observe the direction of the image change of the autocollimator, whether it is closer to or farther from the target position, to determine the grinding direction of the three pads.

[0087] For a given screw, if tightening the screw causes the image from the autocollimator to move closer to the target position, then the post through which the screw passes needs to be ground. If loosening the screw causes the image from the autocollimator to move closer to the target position, then the posts through which the other two screws pass need to be ground. Tighten or loosen each screw to determine which post needs to be ground.

[0088] c. For the pads that need to be ground, calculate the grinding amount according to the grinding amount calculation method and grind them; after grinding, put the pads and screws back in their original positions; rotate the azimuth axis and observe whether the radius of the autocollimator's image return motion trajectory is less than or equal to the required value. If it meets the requirements, this step of installation and adjustment is complete. If it does not meet the requirements, repeat steps a, b, and c, tightening, calculating the grinding amount of the pads, and grinding the process multiple times until the distance between the autocollimator's image return and the target position (i.e., the image return radius) meets the requirements.

[0089] Calculation method for grinding pad amount: The grinding amount Δl of a certain pad that needs to be ground for the second reflector in the i-th time. 2i The calculation formula is as follows:

[0090]

[0091] Where d 2i H is the radius of the self-collimator image return trajectory of a certain pad before the i-th grinding; 2j The height of the support column (there are 3 support columns in total, j refers to a support column included in the mounting bracket of the second reflector), such as Figure 6 As shown.

[0092] d. If the autocollimator image radius is greater than the required value, repeat steps a to c until the autocollimator image radius is less than or equal to the required value.

[0093] e. Lock the azimuth axis, rotate the pitch axis at different angles, observe the autocollimator image return record, and record the motion trajectory points, such as... Figure 5 As shown (the trajectory of the reflected image caused by the elevation axis mirror), when the autocollimator's reflected image radius is less than or equal to the required value, the second reflector is installed and adjusted. If the autocollimator's reflected image radius does not meet the requirements, repeat steps a to e until the requirements are met, then fix the azimuth axis. If steps ② and ③ both meet the requirements, this step will not be repeated.

[0094] f. Use optical structural adhesive to end-seal the screws and secure the two mounting surfaces of the pads to fix the screws in place with the mirror bracket.

[0095] ⑤ First reflecting mirror 2 installation and adjustment

[0096] The installation method of the first reflecting mirror 2 is as follows: Figure 2 As shown, the first reflector 2 is glued to the reflector mount, and the reflector mount is fastened to the base by three shims (adjusting shims) and screws.

[0097] like Figure 7 As shown, the specific steps are as follows:

[0098] a. A measuring camera 84 is installed on the end of the pitch axis of the turntable, and the measuring camera 84 is fixedly connected to the pitch axis 62.

[0099] b. Install a center attenuator 83 between the measuring camera 84 and the turntable. The center attenuator 83 serves a protective function, attenuating the laser energy to prevent damage to operators and instruments.

[0100] c. Power on the laser.

[0101] d. Adjust the shims for the position of the first reflector 2 (laser reflector), keep the pitch axis of the turntable stationary, and rotate the azimuth axis of the turntable to ensure that the position of the centroid of the laser spot formed on the measuring camera changes by less than two pixels; after adjustment, seal the screws with optical structural adhesive.

[0102] The thickness of the three shims is adjusted by grinding. The specific operation process is as follows:

[0103] I. Rotate the azimuth axis 61 at different angles, measure the trajectory of the laser imaging point on the camera as an arc, record the X and Y values ​​of the laser imaging point on the camera, record 5 points, perform least squares fitting on the 5 recorded points to obtain the coordinates of the center and the radius, the position of the center is the target position adjusted from the laser imaging point.

[0104] II. Tighten or loosen the three screws included in the mounting bracket of the first reflector 2, and at the same time observe the direction of the change in the laser imaging point, whether it is closer to or farther from the center, in order to determine the grinding direction of the three pads.

[0105] III. Calculation method for grinding amount of the reflector shim: Grinding amount Δl of the reflector shim 1i The calculation formula is as follows:

[0106]

[0107] Where d 1i Before the i-th grinding of a certain pad of the first reflecting mirror, measure the radius of the trajectory of the laser imaging point on the camera; H 1j The height of the support column (H) 1j The height of the support column (there are 3 support columns in total, j refers to a support column included in the mounting bracket of the first reflector), such as Figure 6 As shown.

[0108] d. When the image radius of the autocollimator 81 is less than two pixels, the adjustment of the first reflector is completed. At this time, use optical structural adhesive to seal the screws and fix the two mounting surfaces of the pad.

[0109] ⑥ Third reflecting mirror 4-piece assembly and adjustment

[0110] The installation method of the third reflecting mirror 4 (optical system reflecting mirror) is as follows: Figure 2As shown. The outer end face of the secondary mirror 52 of the multimode optical system is used as the basis for assembly and adjustment, and the normal of the outer end face of the secondary mirror 52 represents the optical axis direction of the optical system.

[0111] a. Zero-point calibration of visible light cameras. For example... Figure 8 As shown, the third reflecting mirror assembly is installed on the multimode receiving optical system. The autocollimator 81 is set up in front of the secondary mirror 52 and the field of view of the visible light camera 53 of the multimode receiving optical system. The autocollimator 81 is autocollimated with the outer end face of the secondary mirror 52. The attitude of the autocollimator 81 is adjusted so that the image returns to the zero point of the autocollimator. Then, the visible light camera 53 is powered on so that the crosshairs of the autocollimator 81 are imaged in the visible light camera 53. The position of the crosshairs in the camera measurement coordinate system at this time is recorded. This position is the zero point of the visible light camera.

[0112] b. The zero-point projection of the visible light camera 53 onto the measuring camera 84. For example... Figure 9 As shown, firstly, the measuring camera 84 is placed in the light-emitting direction of the third reflecting mirror 4, and an attenuator 85 is installed between the light-emitting direction of the third reflecting mirror 4 and the measuring camera 84. Then, a corner reflector 86 is placed at the front end of the autocollimator 81 and the measuring camera 84, so that the crosshairs of the autocollimator 81 are imaged in the measuring camera 84 after passing through the corner reflector 86. Finally, the laser is powered on, so that the laser beam is reflected by the third reflecting mirror 4 and attenuated by the attenuator 85 before being imaged in the measuring camera 84. The position coordinates (X0, X0) of the crosshairs of the autocollimator in the measuring camera are recorded. This position is the projection position of the zero point of the visible light camera in the measuring camera.

[0113] c. By refining the three pads included in the mounting bracket of the third reflecting mirror, ensure that the deviation between the image of the autocollimator crosshair in the measuring camera (the projection of the zero point of the visible light camera in the measuring camera) and the laser imaging point is within 60″. Disassemble the entire optical system for each adjustment.

[0114] The thickness of the three shims is adjusted by grinding. The specific operation process is as follows:

[0115] Ⅰ. Record the X and Y coordinates of the laser imaging point on the measuring camera.

[0116] II. Tighten or loosen the three screws, and at the same time observe the direction of the image return of the laser imaging point, whether it is closer to or farther away from the zero position of the visible light camera, in order to determine the grinding direction of the three pads.

[0117] III. Calculation method for grinding amount of the shim: Grinding amount Δl of the shim of the third reflecting mirror 3i The calculation formula is as follows:

[0118]

[0119] Where d3i Measure the radius of the laser imaging point's trajectory on the camera before the i-th grinding of a certain pad; H 3j The height of the support column (H) 3j The height of the support column (there are 3 support columns in total, j refers to a support column included in the mounting bracket of the third reflector), such as Figure 6 As shown.

[0120] IV. When the difference between the laser echo point and the zero position is less than the required value, fix the azimuth axis; if the requirement is not met, repeat steps a to c. After the third reflector is adjusted, use optical structural adhesive to seal the screws and fix the mounting surface of the reflector mount.

[0121] The technical solution of this invention is as follows: In a tracking and ranging system composed of a turntable and a multimode optical system, three reflectors are installed. The first reflector is located at the laser's output end, used to deflect the laser beam into the azimuth axis of the turntable; the second reflector is located at the intersection of the azimuth and elevation axes, used to deflect the beam from the azimuth axis into the elevation axis; the third reflector deflects the beam from the elevation axis so that it is parallel to the multimode receiving optical system. The reflectors are installed by gluing them to a reflector mount, which is then secured to the reflector bracket with three posts and screws. The reflector angle is adjusted by grinding the height of the three posts. After installation and adjustment, the reflector support structure is sealed with optical structural adhesive to increase the mechanical stability of the installation and adjustment accuracy.

[0122] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0123] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A method for precise assembly and adjustment of a long-range laser target tracking and ranging optical path, characterized in that, The assembly and adjustment method based on the mounting structure of the long-range laser target tracking and ranging optical path includes: S1: Install a plane mirror (621) leading out from the pitch axis (62) at the light output end of the pitch axis (62); S2: Install an azimuth axis lead-out plane mirror (611) at the light-incident end of the azimuth axis (61); S3: After installing the pitch axis lead-out plane mirror (621) and azimuth axis lead-out plane mirror (611) on the turntable, install and adjust the second reflecting mirror (3); S4: Install and adjust the first reflecting mirror (2); S5: Install and adjust the third reflecting mirror (4); The installation and adjustment of the third reflecting mirror (4) includes: The third reflecting mirror (4) is installed together with the multimode receiving optical system (5). The autocollimator (81) is set up in front of the secondary mirror (52) of the multimode receiving optical system and the field of view of the visible light camera (53). The autocollimator (81) is autocollimated with the outer end face of the secondary mirror (52). The attitude of the autocollimator (81) is adjusted so that the image returns to the zero point of the autocollimator. Then, the visible light camera (53) is powered on so that the crosshairs of the autocollimator (81) are imaged in the visible light camera (53). The position of the crosshairs in the measurement coordinate system of the visible light camera (53) is recorded at this time. This position is the zero point of the visible light camera. The measuring camera is placed in the light-emitting direction of the third reflecting mirror (4), and an attenuator (85) is installed between the light-emitting direction of the third reflecting mirror (4) and the measuring camera. Then, a corner reflector (86) is placed at the front end of the autocollimator (81) and the measuring camera (84) so ​​that the crosshairs of the autocollimator are imaged in the measuring camera (84) after passing through the corner reflector. Finally, the laser is powered on so that the laser beam is reflected by the third reflecting mirror (4) and attenuated by the attenuator (85) before being imaged in the measuring camera. The position coordinates (X0, Y0) of the image of the crosshairs of the autocollimator (81) in the measuring camera (84) are recorded. This position is the projection position of the zero point of the visible light camera in the measuring camera. Adjust the three pads included in the mounting bracket of the third reflector until the deviation between the image of the autocollimator crosshair in the measuring camera and the laser imaging point is within the required value, so that the screws included in the mounting bracket of the third reflector are fixed to the reflector bracket. The mounting structure of the long-range laser target tracking and ranging optical path includes a laser (1), a first reflector (2), a second reflector (3), a third reflector (4), and a multimode receiving optical system (5) arranged sequentially along the optical path. The second reflector (3) is connected to a turntable, which includes an elevation axis (62) and an azimuth axis (61). The azimuth axis (61) rotates around the axis of the azimuth axis (61) along with the elevation axis (62). The elevation axis (62) rotates around its own axis. The elevation axis (62) and the azimuth axis (61) are provided with through holes along their own axial directions, and the through holes of the azimuth axis (61) and the elevation axis (62) are connected. The second reflector (3) is fixedly connected inside the elevation axis (62). The multimode receiving optical system (5) is fixedly connected to the elevation axis (62). The third reflector is fixedly connected to the multimode receiving optical system (5). The first reflector (2) is connected to the first reflector (3). The first reflector (2), the second reflector (3), and the third reflector (4) are all fixed by mounting brackets. The mounting brackets include a reflector base (72), a reflector bracket (71), a pad (73), and a screw (74). The first reflector (2), the second reflector (3), or the third reflector (4) are installed on the reflector base (72) by adhesive bonding. There are three pads (73) and three screws (74). The three pads (73) are located between the reflector base (72) and the reflector bracket (71). The screws (74) pass through the reflector base (72) and the pads (73) and are threaded to the reflector bracket (71) so that the reflector base (72) is fastened to the reflector bracket (71) by the three pads (73) and the screws (74). The angle of each first reflector (2), second reflector (3), or third reflector (4) is adjusted by grinding the height of the three pads (73).

2. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 1, characterized in that, The installation of a pitch axis lead-out plane mirror (621) at the light output end of the pitch axis (62) includes: Place the turntable horizontally on the optical platform and fix the azimuth axis to ensure that the turntable can only rotate on the pitch axis. A pitch axis lead-out plane mirror (621) is installed at the light output end of the pitch axis, and an autocollimator (81) is set up in front of the pitch axis lead-out plane mirror so that the autocollimator is autocollimated to the pitch axis lead-out plane mirror. Continuously rotate the pitch axis of the turntable and adjust the orientation of the normal of the pitch axis-leading plane mirror until the diameter of the crosshair circle drawn by the autocollimator is within the required value, and fix the relative position of the pitch axis-leading plane mirror and the pitch axis.

3. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 1, characterized in that, The installation of the azimuth axis lead-out plane mirror (611) at the light incident end of the azimuth axis (61) includes: Raise the turntable as a whole, and install the azimuth axis lead-out plane mirror (611) at the interface at the bottom of the azimuth axis; A 45° reflector (82) is fixedly installed directly below the azimuth axis of the turntable, and an autocollimator (81) is set up so that the 45° reflector (82) is within the field of view of the autocollimator (81), and the autocollimator (81) leads out a plane mirror for autocollimation of the azimuth axis. Rotate the azimuth axis of the turntable and adjust the direction of the normal of the azimuth axis-leading plane mirror until the diameter of the crosshair circle drawn by the autocollimator is within the required value. Fix the relative position of the azimuth axis-leading plane mirror and the azimuth axis.

4. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 3, characterized in that, The installation and adjustment of the second reflecting mirror includes: S31: Keep the positions of the autocollimator (81), 45° reflector (82) and turntable unchanged when the azimuth axis lead-out plane mirror is installed at the light-incident end of the azimuth axis; S32: Install the three support pillars, mirror mount, mirror bracket, and second mirror of the second reflector; lock the pitch axis of the turntable, rotate the azimuth axis of the turntable, and observe the diameter of the autocollimator's image return circle. If it is less than or equal to the required value, the second reflector installation and adjustment are complete; if it is greater than the required value, precisely install and adjust the second reflector until the diameter of the autocollimator's image return circle is less than or equal to the required value; lock the azimuth axis, rotate the pitch axis, and observe the diameter of the autocollimator's image return circle. If it is confirmed to be less than or equal to the required value, the second reflector installation and adjustment are complete.

5. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 4, characterized in that, The precision assembly and adjustment of the second reflecting mirror includes: S321: Rotate the azimuth axis to different angles multiple times and record multiple autocollimator image return positions; S322: Perform least-squares fitting on multiple autocollimator image positions to obtain the center coordinates and radius of the circle. The center coordinates are the target position for autocollimator image adjustment. S323: Tighten or loosen each of the three screws in the mounting bracket of the second reflector in sequence, while simultaneously observing the direction of change of the image returned by the autocollimator, whether it is moving closer to or away from the target position, to determine the pads that need to be ground: when a screw is tightened and the image returns closer to the center, the height of the pad corresponding to that screw is ground, and the grinding amount is obtained through calculation; when a screw is loosened and the image returns closer to the center, the pads corresponding to the other two screws are ground, and the grinding amount is obtained through calculation. S324: For a pad that needs to be ground, tighten the pad and record the change in the image angle on the autocollimator caused by tightening the pad. Calculate the grinding amount of the pad based on the change in the image angle, grind according to the grinding amount of the pad, and record the distance between the image of the autocollimator and the target position after grinding. S325: If the distance between the image returned by the autocollimator in S324 and the target position does not meet the requirements, repeat S324 for the same pad until the distance between the image returned by the autocollimator and the target position meets the requirements, and then continue to grind the next pad that needs to be ground through S324.

6. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 5, characterized in that: The amount of grinding done on the i-th time for a certain pad that needs grinding on the second reflector. Δl 2i The calculation formula is as follows: Where, d 2i H represents the change in the image angle on the autocollimator caused by the i-th tightening adjustment of a certain shim of the second reflector; 2j The height of the support column.

7. The precision assembly and adjustment method for the long-range laser target tracking and ranging optical path according to claim 1, characterized in that, The installation and adjustment of the first reflecting mirror (2) includes: A measuring camera (84) is fixedly installed at the light output end of the pitch axis; A center attenuator (83) is installed between the measuring camera (84) and the pitch axis (62); A first reflector (2) is mounted on a support directly below the azimuth axis and a laser (1) is installed thereon. The light emitted by the laser is used as the incident light of the first reflector. Keep the pitch axis of the turntable stationary, rotate the azimuth axis of the turntable, and adjust the thickness of the pads included in the mounting bracket of the first reflector until the change in the centroid position of the laser spot formed on the measuring camera is less than the required value, so that the screws included in the mounting bracket of the first reflector are fixed to the reflector bracket.

Images