Mounting structure of long-distance laser target tracking distance measuring light path and precise assembling and adjusting method of long-distance laser target tracking distance measuring light path

Abstract

The invention relates to an installation structure and a precision adjustment method of a long-distance laser target tracking and ranging light path, which are used for high-precision adjustment of a laser emission direction of a space target tracking and ranging light path. And the deviation between the emergent direction of the laser reflected by the three reflectors and the swing angle of the rotary table is minimum. The method comprises the following steps: firstly, leading a pitch axis and an azimuth axis to a plane mirror by using an autocollimator; secondly, a second reflecting mirror and a first reflecting mirror are installed and adjusted through the installation mode of a cushion column and a fastening screw, the grinding amount of the cushion column is calculated according to the back image motion track of an autocollimator or the motion track of a laser imaging point in a measurement camera, the cushion column is ground on the basis, and the purpose of high-precision installation and adjustment is achieved; thirdly, through zero calibration of a visible light camera, a measurement camera and a corner reflector, an adjustment system of a third reflector is built, and adjustment of the third reflector is achieved; finally, the cushion columns and the fastening screws are reinforced through epoxy glue, and the mechanical resistance of the light path is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical path alignment, and particularly relates to a precise alignment of a spatial long-distance laser target tracking and ranging optical path. Background Art

[0002] The long-distance laser tracking and ranging system belongs to an optoelectronic tracking and aiming system, and has been increasingly applied in the aerospace field in recent years. The long-distance laser tracking and ranging system integrates the tracking turntable and the outgoing optical path of the laser, and uses a Coudé mirror to make the laser outgoing direction consistent with the turntable tracking direction. The alignment of the Coudé optical path requires high precision, great difficulty, and long time; for a laser tracking and ranging system used in space, on the premise of achieving alignment precision, it is also necessary to improve the anti-mechanical performance, that is, the alignment precision needs to remain stable after experiencing a vibration environment. Summary of the Invention

[0003] The technical problem solved by this application is: overcoming the deficiencies of the prior art, providing a precise alignment method for a long-distance laser target tracking and ranging optical path, and the lidar has high resolution, high imaging frame rate, high measurement precision, and long working distance.

[0004] The technical problem solved by the present invention is: in a long-distance laser tracking and ranging system, accurately and real-time aligning the laser emission direction with the turntable rotation axis, that is, when the turntable swings at a certain angle around two axes, the laser outgoing light also swings by the same angle. The laser emission direction is realized by three reflecting mirrors, so the angles of the reflecting mirrors need to be precisely aligned to ensure the real-time alignment of the laser emission direction with the turntable rotation axis.

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

[0006] An installation structure for a long-distance laser target tracking and ranging optical path, the long-distance laser target tracking and ranging optical path, including a laser, a first reflector, a second reflector, a third reflector, and a multimode receiving optical system arranged in sequence along the optical path. The second reflector is connected to a turntable, where the turntable includes a pitch axis and a azimuth axis. The azimuth axis drives the pitch axis to rotate around the axis of the azimuth axis; the pitch axis rotates around its own axis; through holes are provided along the axis directions of the pitch axis and the azimuth axis, and the through hole of the azimuth axis communicates with the through hole of the pitch axis. 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 fixedly connected to the multimode receiving optical system. The first reflector, the second reflector, and the third reflector are all installed by fixing supports. The fixing support includes a mirror base, a mirror support, cushion posts, and screws. The first reflector, the second reflector, or the third reflector is installed on the mirror base by gluing. Three cushion posts and three screws are provided. The three cushion posts are all located between the mirror base and the mirror support. The screws pass through the mirror base and the cushion posts and are threadedly connected to the mirror support, so that the mirror base is fastened to the mirror support through the three cushion posts and screws; by grinding the heights of the three cushion posts, the angles of each of the first reflector, the second reflector, or the third reflector are adjusted.

[0007] Based on the above installation structure adjustment method for the long-distance laser target tracking and ranging optical path, it includes:

[0008] S1: Install a pitch axis extraction flat mirror at the light output end of the pitch axis;

[0009] S2: Install an azimuth axis extraction flat mirror at the light input end of the azimuth axis;

[0010] S3: On the basis of installing the pitch axis extraction flat mirror and the azimuth axis extraction flat mirror on the turntable, adjust the second reflector;

[0011] S4: Adjust the first reflector;

[0012] S5: Adjust the third reflector.

[0013] Further, the installation of the pitch axis extraction flat mirror at the light output end of the pitch axis includes:

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

[0015] Install a pitch axis extraction flat mirror at the light output end of the pitch axis, and set up an autocollimator directly in front of the pitch axis extraction flat mirror to make the autocollimator autocollimate to the pitch axis extraction flat mirror;

[0016] Continuously rotate the pitch axis of the turntable and adjust the installation and alignment normal direction of the pitch axis leading-out flat mirror until the diameter of the cross-image circle of the autocollimator is within the required value, and fix the relative position of the pitch axis leading-out flat mirror and the pitch axis.

[0017] Further, installing the azimuth axis leading-out flat mirror at the light incident end of the azimuth axis includes:

[0018] Lift the turntable as a whole, install an interface at the bottom of the azimuth axis to install the azimuth axis leading-out flat mirror;

[0019] Fix and install a 45° reflecting mirror directly below the azimuth axis of the turntable, and set up an autocollimator so that the 45° reflecting mirror is within the field of view of the autocollimator, and make the autocollimator self-align with the azimuth axis leading-out flat mirror;

[0020] Rotate the azimuth axis of the turntable and adjust the normal direction of the azimuth axis leading-out flat mirror until the diameter of the cross-image circle of the autocollimator is within the required value, and fix the relative position of the azimuth axis leading-out flat mirror and the azimuth axis.

[0021] Further, the alignment and adjustment of the second reflecting mirror includes:

[0022] S31: Keep the positions of the autocollimator, the 45° reflecting mirror and the turntable unchanged when installing the azimuth axis leading-out flat mirror at the light incident end of the azimuth axis;

[0023] S32: Install the three cushion posts, the mirror base, the mirror support and the second reflecting mirror of the second reflecting mirror; lock the pitch axis of the turntable and do not move it, rotate the azimuth axis of the turntable, observe the diameter of the image circle of the autocollimator. If it is less than or equal to the required value, the alignment and adjustment of the second reflecting mirror is completed; if it is greater than the required value, perform precise alignment and adjustment on the second reflecting mirror until the diameter of the image circle of the autocollimator is less than or equal to the required value; lock the azimuth axis and do not move it, rotate the pitch axis, observe the diameter of the image circle of the autocollimator, and confirm that it is less than or equal to the required value, and the alignment and adjustment of the second reflecting mirror is completed.

[0024] Further, the precise alignment and adjustment of the second reflecting mirror includes:

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

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

[0027] S323: Tighten or loosen each of the three screws included in the mounting support of the second mirror in sequence, and at the same time observe the change direction of the reflected image of the autocollimator, whether it is approaching or moving away from the target position, to determine the spacer column that needs to be ground: When tightening a certain screw and the reflected image approaches the center of the circle, grind the height of the spacer column corresponding to this screw, and the grinding amount is obtained through calculation; when loosening a certain screw and the reflected image approaches the center of the circle, grind the spacer columns corresponding to the other two screws, and the grinding amount is obtained through calculation;

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

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

[0030] Further, the grinding amount Δl of the i-th time of a certain spacer column that needs to be ground of the second mirror 2i The calculation formula is:

[0031] Among them, d 2i is the change amount of the reflected image angle on the autocollimator caused by the i-th tightening adjustment of a certain spacer column of the second mirror; H 2j is the height of this spacer column.

[0032] Further, the alignment and adjustment of the first mirror includes:

[0033] Fix and install a measurement camera at the light-emitting end of the pitch axis;

[0034] Install a central attenuation sheet between the measurement camera and the pitch axis;

[0035] Erect the first mirror through the mounting support of the first mirror directly below the azimuth axis, and install a laser. The light emitted by the laser serves as the incident light of the first mirror;

[0036] Keep the pitch axis of the turntable stationary, rotate the azimuth axis of the turntable, and adjust the thickness of the spacer column included in the mounting support of the first mirror until the change in the centroid position of the light spot formed by the laser on the measurement camera is less than the required value, and fix the screws included in the mounting support of the first mirror to the mirror support.

[0037] Further, the alignment and adjustment of the third mirror includes:

[0038] Install the third mirror together with the multimode receiving optical system. Set up the autocollimator directly in front of the secondary mirror of the multimode receiving optical system and the field of view of the visible light camera. The autocollimator performs autocollimation on the outer end face of the secondary mirror, and adjust the attitude of the autocollimator to make the returned image reach the zero point of the autocollimator. Then, power on the visible light camera, so that the crosshair of the autocollimator is imaged in the visible light camera, and record the position of the crosshair in the measurement coordinate system of the visible light camera. This position is the zero point of the visible light camera.

[0039] Place the measurement camera in the light output direction of the third mirror, and install an attenuation sheet between the light output direction of the third mirror and the measurement camera. Then, place a corner reflector in front of the autocollimator and the measurement camera, so that the crosshair of the autocollimator passes through the corner reflector and is imaged in the measurement camera. Finally, power on the laser, so that the emitted laser light is reflected by the third mirror, attenuated by the attenuation sheet, and then imaged in the measurement camera. Record the position coordinates (X0, X0) of the image of the autocollimator crosshair in the measurement camera. This position is the projection position of the zero point of the visible light camera in the measurement camera.

[0040] Adjust the three cushion posts included in the mounting support of the third mirror until the deviation between the image of the autocollimator crosshair in the measurement camera and the laser imaging point is within the required value, and fix the screws included in the mounting support of the third mirror to the mirror support.

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

[0042] (1) The present invention gives a calculation formula for the grinding amount of the cushion posts during the alignment of the mirror. Compared with the traditional alignment method, it has a clear direction and can significantly improve the alignment accuracy and efficiency.

[0043] (2) For the alignment of the Coudé mirrors (the first mirror and the second mirror), mainly align by rotating the azimuth axis and use the rotation of the pitch axis as an auxiliary verification, avoiding the repeated alignment process that considers both the azimuth axis and the pitch axis, and improving the alignment efficiency.

[0044] (3) After the alignment of the mirror is completed, the installation surface of the mirror support structure is sealed with an optical structural adhesive to increase the mechanical stability of the alignment accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the alignment flow chart;

[0046] Figure 2 is the schematic diagram of the mirror installation method;

[0047] Figure 3 is the schematic diagram of the alignment of the turntable pitch axis exit mirror;

[0048] Figure 4This is a schematic diagram of the installation and 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 reflector;

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

[0051] Figure 7 adjusting a light path diagram for the first reflector;

[0052] Figure 8 This is a schematic diagram of the zero point calibration of a visible light camera;

[0053] Figure 9 This is a schematic diagram of the installation and adjustment of the reflector of the optical system;

[0054] Figure 10 Schematic diagram of the light path.

[0055] Description of the accompanying drawings: 1. laser; 2. first reflector; 3. second reflector; 4. third reflector; 5. multi-mode receiving optical system;

[0056] 51. Multi-mode receiving optical system housing; 52. Secondary mirror; 53. Visible light camera;

[0057] 61, azimuth axis; 611, azimuth axis leads to plane mirror; 62, elevation axis; 621, elevation axis leads to plane mirror;

[0058] 71. reflector bracket; 72. reflector seat; 73. pad column; 74. screw;

[0059] 81. Autocollimator; 82. 45° reflector; 83. Center attenuation plate; 84. Measuring camera; 85. Attenuation plate; 86. Corner reflector. DETAILED DESCRIPTION

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

[0061] A precision adjustment method for long-distance laser target tracking and ranging optical path, such as Figure 10As shown in the figure, 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 in sequence along the optical path. The second reflector 3 is installed on a turntable, where the turntable includes a pitch axis 62 and a azimuth axis 61. The azimuth axis 61 drives the pitch axis 62 to rotate around the axis of the azimuth axis 61; the pitch axis 62 rotates around its own axis; through holes are provided along the axial directions of the pitch axis 62 and the azimuth axis 61, and the through hole of the azimuth axis 61 communicates with the through hole of the pitch axis 62. The second reflector 3 is fixedly connected inside the azimuth axis. The multimode receiving optical system 5 is fixedly connected to the pitch axis 62; the third reflector 4 is fixedly connected to the multimode receiving optical system. Among them, the first reflector 2 is located at the light-emitting end of the laser, and is used to deflect the laser output light of the laser 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 of the azimuth axis into the pitch axis; the third reflector is used to deflect the output light of 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. The first reflector 2, the second reflector 3, and the third reflector 4 are all called reflector bodies. The mounting bracket includes a mirror base 72, a mirror support 71, a spacer column 73, and a screw 74. The reflector body is mounted on the mirror base by bonding. Three spacer columns and three screws are provided. The three spacer columns are all located between the mirror base and the mirror support. The screw passes through the mirror base and the spacer column and is threadedly connected to the mirror support, so that the mirror base is fastened to the mirror support through the three spacer columns and screws. By grinding the heights of the three spacer columns, the angle of each reflector body (i.e., the first reflector, the second reflector, or the third reflector) is adjusted.

[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] The embodiment of the present application discloses a precise alignment method for a long-distance laser target tracking and ranging optical path, including the alignment process of the laser emission optical path, the tooling and equipment used for aligning the three reflectors, the installation method and adjustment method of the reflectors, the details of the alignment process, and other contents.

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

[0066] The alignment process is divided into 6 steps, as Figure 1 shown, and the specific alignment process is as follows:

[0067] ① Alignment preparation

[0068] It includes a turntable, a second reflector 3, a first reflector 2, a third reflector 4, a support structure, etc. in the laser emission optical path, 2 sets of autocollimators, 1 set each of a corner reflector, a measurement camera, and a 45-degree tooling reflector, 2 sets of outgoing plane mirror assemblies, and an optical structure, etc.

[0069] ② Alignment of the outgoing plane mirror on the pitch axis

[0070] As Figure 3 shown, the specific steps for aligning the outgoing plane mirror 621 on the pitch axis are as follows:

[0071] a. Place the turntable horizontally on the optical bench, fix the azimuth axis 61, and ensure that the turntable can only rotate around the pitch axis 62.

[0072] b. Install the 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 a transmissive inner ring (the middle transmissive area is not less than 8 mm) and a reflective outer ring. The normal of this pitch axis outgoing plane mirror needs to be adjustable along the two axes. Both surfaces of the pitch axis outgoing plane mirror can reflect and transmit light.

[0073] c. Use the autocollimator 81 to align the pitch axis outgoing plane mirror 621. The autocollimator 81 is set up directly in front of the pitch axis outgoing plane mirror 621, and autocollimation is performed on this pitch axis outgoing plane mirror 621. Continuously rotate the pitch axis of the turntable and adjust the alignment normal direction of the pitch axis outgoing plane mirror to ensure that the diameter of the crosshair image circle of the autocollimator is within 2″ (adjust the autocollimator to ensure that the autocollimation image is near X = 0 and Y = 0 to improve the measurement accuracy).

[0074] ③ Alignment of the outgoing plane mirror 611 on the azimuth axis

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

[0076] a. Raise the entire turntable by no less than 200 mm, and install the outgoing plane mirror 611 on the azimuth axis at the bottom of the azimuth axis 61. Both surfaces of the outgoing plane mirror 611 on the azimuth axis can reflect and transmit light.

[0077] b. Fix and install a 45° reflector 82 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 to align the outgoing plane mirror 611 on the azimuth axis. The autocollimator 81 is set up as Figure 4 shown, perform autocollimation on the outgoing plane mirror on the azimuth axis, rotate the azimuth axis of the turntable, and adjust the normal direction of the outgoing plane mirror on the azimuth axis to ensure that the diameter of the crosshair image circle of the autocollimator is within 2″ (adjust the autocollimator to ensure that the autocollimation image is near X = 0 and Y = 0 to improve the measurement accuracy).

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

[0080] ④ Adjustment and installation of the second mirror 3

[0081] The purpose of adjusting and installing the second mirror 3 (turntable mirror) is to make the azimuth axis 61 and the elevation axis 62 of the turntable form a reflection optical path along the normal of the second mirror 3 (turntable mirror), that is, when light is incident from one rotation axis, it exits from the other rotation axis after passing through the mirror.

[0082] The installation method of the second mirror is as Figure 2 shown. The second mirror is bonded to the mirror base by gluing, and the mirror base is fastened to the mirror support by 3 spacer posts and screws. The mirror support is fastened to the azimuth axis and moves with the azimuth axis, not with the elevation axis.

[0083] As Figure 5 shown, keep the positions of the autocollimator 81, the 45° mirror 82 and the turntable unchanged during the adjustment of the azimuth-axis exit plane mirror 611. Install the mirror base on the mirror support; lock the elevation axis 62 of the turntable and keep it stationary, rotate the azimuth axis 61 of the turntable, and adjust the thickness of the spacer posts of the mirror base so that the diameter of the crosshair image circle of the autocollimator is within the required value; after adjustment, install the screws and seal the ends with optical structural adhesive.

[0084] Among them, the thicknesses of the three spacer posts are adjusted by grinding. The specific operation process is as follows:

[0085] a. Rotate the azimuth axis at different angles. The movement trajectory of the autocollimator image is an arc. Record the X and Y values of the movement trajectory, and the number of recording points is not less than 5. Perform least squares fitting on the 5 recorded points to obtain the center coordinate values and the radius. The center position (i.e., the center coordinate values) is the target position for adjusting the autocollimator image, as Figure 6 shown.

[0086] b. Tighten or loosen each of the 3 screws in turn, and at the same time observe the change direction of the autocollimator image, whether it is approaching or moving away from the target position, so as to determine the grinding directions of the three spacer posts.

[0087] For a certain screw, if the autocollimator image moves towards the target position when the screw is tightened, the spacer post through which the screw passes needs to be ground; if the autocollimator image moves towards the target position when the screw is loosened, the spacer posts through which the other two screws pass need to be ground. Tighten or loosen each screw to determine the spacer posts that need to be ground.

[0088] c. For the pad columns that need to be ground, calculate the grinding amount according to the grinding amount calculation method and perform grinding; after grinding is completed, reinstall the pad columns and screws in their original positions; rotate the azimuth axis and observe whether the radius of the retroimage movement trajectory of the autocollimator is less than or equal to the required value. If it meets the requirement, this step of alignment and adjustment is completed. If it does not meet the requirement, then repeat steps a, b, and c, and perform multiple tightening operations, calculate the grinding amount of the pad columns, and the grinding process until the distance (i.e., the retroimage radius) between the retroimage of the autocollimator and the target position meets the requirement.

[0089] Grinding amount calculation method for pad columns: The grinding amount Δl of the i-th pad column that needs to be ground on the second mirror 2i is calculated by the following formula:

[0090]

[0091] where d 2i is the radius of the retroimage movement trajectory of the autocollimator before the i-th grinding of a certain pad column; H 2j is the height of this pad column (there are a total of 3 pad columns, and j refers to a certain pad column included in the mounting support of the second mirror), as Figure 6 shown.

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

[0093] e. Lock the azimuth axis, rotate the pitch axis at different angles, observe the retroimage of the autocollimator and record the movement trajectory points, as Figure 5 shown (the retroimage movement trajectory caused by the reflection of the mirror led out by the pitch axis). When the retroimage radius of the autocollimator is less than or equal to the required value, the alignment and adjustment of the second mirror is completed; if the retroimage radius of the autocollimator does not meet the requirement, repeat steps a to e until it meets the requirement, and then fix the azimuth axis. If the alignment and adjustment processes in steps ② and ③ both meet the index requirements, this step will not be repeated.

[0094] f. Seal the screws with optical structural adhesive and seal the two mounting surfaces of the pad columns to fix the positions of the screws and the mirror support.

[0095] ⑤ Alignment and adjustment of the first mirror 2

[0096] The mounting method of the first mirror 2 is as Figure 2 shown, where the first mirror 2 is bonded to the mirror seat by adhesive bonding, and the mirror seat is fastened to the base through 3 pad columns (adjusting shims) and screws.

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

[0098] a. Install the measurement camera 84 at the shaft end of the turntable pitching axis. The measurement camera 84 is fixedly connected to the pitching axis 62.

[0099] b. Install the central attenuation sheet 83 between the measurement camera 84 and the turntable. The central attenuation sheet 83 plays a protective role, attenuating the laser energy to avoid damaging the operator and the instrument.

[0100] c. Power on the laser.

[0101] d. Adjust the spacer columns at the position of the first mirror 2 (laser mirror). Keep the turntable pitching axis stationary and rotate the turntable azimuth axis to ensure that the change in the centroid position of the light spot formed by the laser on the measurement camera is less than two pixels; after adjustment, install the screws and seal the ends with optical structural adhesive.

[0102] Among them, the thickness of the three spacer columns is adjusted by grinding. The specific operation process is as follows:

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

[0104] Ⅱ. Tighten or loosen the 3 screws included in the mounting bracket of the first mirror 2, and at the same time observe the change direction of the return image of the laser imaging point, whether it is approaching or moving away from the center of the circle, to determine the grinding direction of the three spacer columns.

[0105] Ⅲ. Calculation method for the grinding amount of the spacer column: The grinding amount Δl 1i of the spacer column of the mirror is calculated by the following formula:

[0106]

[0107] where d 1i is the radius of the movement trajectory of the laser imaging point on the measurement camera before the i-th grinding of a certain spacer column of the first mirror; H 1j is the height of the spacer column (H 1j is the height of this spacer column (there are a total of 3 spacer columns, and j refers to a certain spacer column included in the mounting bracket of the first mirror), as Figure 6 shown.

[0108] d. When the radius of the return image of the autocollimator 81 is less than two pixels, the adjustment of the first mirror is completed. At this time, seal the screws with optical structural adhesive and seal the two mounting surfaces of the spacer column.

[0109] ⑥ Alignment and adjustment of the third mirror 4

[0110] The installation method of the third mirror 4 (optical system mirror) is as Figure 2As shown in the figure, the outer end face of the secondary mirror 52 of the multi-mode optical system is used as the alignment basis, and the normal line of the outer end face of the secondary mirror 52 represents the optical axis direction of the optical system.

[0111] a. Zero calibration of the visible light camera. As Figure 8 shown in the figure, install the third mirror assembly on the multi-mode receiving optical system, place the autocollimator 81 directly in front of the field of view of the secondary mirror 52 and the visible light camera 53 of the multi-mode receiving optical system. The autocollimator 81 performs autocollimation on the outer end face of the secondary mirror 52, and adjust the attitude of the autocollimator 81 to make the returned image reach the zero point of the autocollimator; then, power on the visible light camera 53, so that the crosshair of the autocollimator 81 is imaged in the visible light camera 53, and record the position of the crosshair in the camera measurement coordinate system at this time. This position is the zero point of the visible light camera.

[0112] b. Project the zero point of the visible light camera 53 onto the measurement camera 84. As Figure 9 shown in the figure, first, place the measurement camera 84 in the light output direction of the third mirror 4, and install an attenuation sheet 85 between the light output direction of the third mirror 4 and the measurement camera 84; then, place a corner reflector 86 in front of the autocollimator 81 and the measurement camera 84, so that the crosshair of the autocollimator 81 passes through the corner reflector 86 and is imaged in the measurement camera 84; finally, power on the laser, so that the laser output light is reflected by the third mirror 4 and attenuated by the attenuation sheet 85 and then imaged in the measurement camera 84, and record the position coordinates (X0, X0) of the crosshair of the autocollimator in the measurement camera. This position is the projection position of the zero point of the visible light camera in the measurement camera.

[0113] c. By grinding the three cushion posts included in the mounting support of the third mirror, ensure that the deviation between the image of the autocollimator crosshair in the measurement camera (the projection of the zero point of the visible light camera in the measurement camera) and the laser imaging point is within 60″. The entire optical system is removed during each adjustment.

[0114] Among them, the thickness of the three cushion posts is adjusted by grinding. The specific operation process is as follows:

[0115] Ⅰ. Record the coordinate values of the laser imaging point on the measurement camera in the X and Y directions.

[0116] Ⅱ. Tighten or loosen the 3 screws, and at the same time observe the change direction of the returned image of the laser imaging point, whether it is approaching or moving away from the zero position of the visible light camera, to determine the grinding direction of the three cushion posts.

[0117] Ⅲ. Calculation method for the grinding amount of the cushion post: The grinding amount Δl 3i of the cushion post of the third mirror is calculated by the following formula:

[0118]

[0119] Among them, d3i is the radius of the movement trajectory of the laser imaging point on the measurement camera before the i-th grinding of a certain spacer column; H 3j is the height of the spacer column (H 3j is the height of this spacer column (there are a total of 3 spacer columns, and j refers to a certain spacer column included in the mounting support of the third mirror), as Figure 6 shown.

[0120] Ⅳ. When the difference between the laser return image point and the zero position is less than the required value, fix the azimuth axis; if it does not meet the requirements, repeat steps a to c. After the adjustment of the third mirror is completed, at this time, use an optical structural adhesive to seal the screw end and seal the mounting surface of the mirror seat.

[0121] The technical solution of the present invention is: in a tracking and ranging system composed of a turntable and a multimode optical system, three mirrors are installed. Among them, the first mirror is located at the light-emitting end of the laser, and is used to deflect the laser light emitted by the laser into the azimuth axis of the turntable; the second mirror is located at the intersection of the azimuth axis and the pitch axis, and is used to deflect the light of the azimuth axis into the pitch axis; the third mirror is used to deflect the outgoing light of the pitch axis and make it parallel to the multimode receiving optical system. Among them, the installation method of the mirror: the mirror is installed on the mirror seat by means of bonding, the mirror seat is fastened to the mirror support through three spacer columns and screws, and the angle of the mirror is adjusted by grinding the heights of the three spacer columns; after the alignment and adjustment are completed, the mirror support structure is sealed with an optical structural adhesive to increase the mechanical stability of the alignment and adjustment accuracy.

[0122] The content not described in detail in the specification of this application belongs to the well-known technology of those skilled in the art.

[0123] The above has described this application in detail in combination with specific embodiments and exemplary examples, but these descriptions should not be construed as limitations on this application. Those skilled in the art understand that without departing from the spirit and scope of this application, various equivalent replacements, modifications or improvements can be made to the technical solution and its implementation manner of this application, and these all fall within the scope of this application. The protection scope of this application is subject to the appended claims.

Claims

1. An installation structure for a long-distance laser target tracking and ranging optical path, the long-distance laser target tracking and ranging optical path, a laser (1), a first reflector (2), a second reflector (3), a third reflector (4) and a multi-mode receiving optical system (5) are arranged in sequence along the optical path, the second reflector (3) is connected to a turntable, wherein the turntable comprises a pitch axis (62) and an azimuth axis (61), the azimuth axis (61) rotates around the axis of the azimuth axis (61) together with the pitch axis (62); the pitch axis (62) rotates around its own axis; the pitch axis (62) and the azimuth axis (61) are provided with through holes along their own axis directions, and the through hole of the azimuth axis (61) is connected to the through hole of the pitch axis (62), and the second reflector (3) is fixedly connected to the azimuth axis (61). The multi-mode receiving optical system (5) is fixedly connected to the pitch axis (62); the third reflector is fixedly connected to the multi-mode receiving optical system (5), characterized in that: The first reflector (2), the second reflector (3) and the third reflector (4) are all fixed by means of a mounting support, the mounting support comprising a reflector seat (72), a reflector bracket (71), a pad column (73) and a screw (74), the first reflector (2), the second reflector (3) or the third reflector (4) are mounted on the reflector seat (72) by means of adhesive bonding, three pad columns (73) and three screws (74) are provided, the three pad columns (73) are all located between the reflector seat (72) and the reflector bracket (71), the screw (74) passes through the reflector seat (72) and the pad columns (73) and is threadedly connected to the reflector bracket (71), so that the reflector seat (72) is fastened to the reflector bracket (71) by means of the three pad columns (73) and the screw (74); the angle of each first reflector (2), the second reflector (3) or the third reflector (4) is adjusted by grinding the height of the three pad columns (73).

2. A precise adjustment method for long-distance laser target tracking and ranging optical path, characterized in that: The method for assembling and adjusting the installation structure of the long-distance laser target tracking and ranging optical path according to claim 1 comprises: S1: Installing a pitch axis lead-out plane mirror (621) at the light-emitting end of the pitch axis (62); S2: installing an azimuth axis lead-out plane mirror (611) at the light incident end of the azimuth axis (61); S3: After the elevation axis lead-out plane mirror (621) and the azimuth axis lead-out plane mirror (611) are installed on the turntable, the second reflector (3) is installed and adjusted; S4: adjusting the first reflecting mirror (2); S5: Install and adjust the third reflecting mirror (4).

3. The precise adjustment method for long-distance laser target tracking and ranging optical path according to claim 2 is characterized in that: The pitch axis lead-out plane mirror (621) is installed at the light-emitting end of the pitch axis (62), comprising: Place the turntable horizontally on the optical platform and fix the azimuth axis to ensure that the turntable can only rotate along the pitch axis; A pitch axis lead-out plane mirror (621) is installed at the light-emitting end of the pitch axis, and an autocollimator (81) is set up right in front of the pitch axis lead-out plane mirror so that the autocollimator can self-collimate the pitch axis lead-out plane mirror; Continuously rotate the pitch axis of the turntable and adjust the normal direction of the pitch axis lead-out plane mirror until the diameter of the autocollimator cross-image circle is within the required value, and fix the relative position of the pitch axis lead-out plane mirror and the pitch axis.

4. The method for precise adjustment of the optical path of long-distance laser target tracking and ranging according to claim 2 is characterized in that: The azimuth axis lead-out plane mirror (611) is installed at the light incident end of the azimuth axis (61), comprising: The turntable is lifted as a whole, and an azimuth axis lead-out plane mirror (611) is installed at the installation 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) so that the autocollimator (81) can align the plane mirror with respect to the azimuth axis; Rotate the azimuth axis of the turntable and adjust the normal direction of the azimuth axis lead-out plane mirror until the diameter of the autocollimator cross-image circle is within the required value, and fix the relative position of the azimuth axis lead-out plane mirror and the azimuth axis.

5. The method for precise adjustment of the optical path of long-distance laser target tracking and ranging according to claim 4 is characterized in that: The step of adjusting the second reflector comprises: S31: Keeping the positions of the autocollimator (81), the 45° reflector (82) and the turntable unchanged when the azimuth axis lead-out plane mirror is installed at the light input end of the azimuth axis; S32: Install the three cushion columns, reflector seat, reflector bracket and second reflector of the second reflector; lock the pitch axis of the turntable, rotate the azimuth axis of the turntable, observe the diameter of the autocollimator image return circle, if it is less than or equal to the required value, the second reflector is installed and adjusted; if it is greater than the required value, fine-tune the second reflector until the diameter of the autocollimator image return circle is less than or equal to the required value; lock the azimuth axis, rotate the pitch axis, observe the diameter of the autocollimator image return circle, confirm that it is less than or equal to the required value, and the second reflector is installed and adjusted.

6. The method for precise adjustment of the optical path of long-distance laser target tracking and ranging according to claim 5 is characterized in that: The precise adjustment of the second reflector comprises: S321: rotating the azimuth axis to different angles multiple times, and recording multiple autocollimator echo positions; S322: performing least square fitting on a plurality of autocollimator echo positions to obtain a circle center coordinate value and a radius, wherein the circle center coordinate value is a target position for autocollimator echo adjustment; S323: Tighten or loosen each of the three screws included in the mounting bracket of the second reflector in turn, and simultaneously observe the changing direction of the image return of the autocollimator, whether it is close to or away from the target position, to determine the pad column that needs to be ground: when a certain screw is tightened and the image return is close to the center of the circle, the pad column height corresponding to the screw is ground, and the grinding amount is obtained by calculation; when a certain screw is loosened and the image return is close to the center of the circle, the pad columns corresponding to the other two screws are ground, and the grinding amounts are obtained by calculation; S324: for a pad column that needs to be ground, tighten the pad column that needs to be ground, and record the change in the image return angle on the autocollimator caused by the tightening of the pad column, calculate the pad column grinding amount according to the image return angle change, grind according to the pad column grinding amount, and record the distance between the image return of the autocollimator and the target position after grinding; S325: If the distance between the echo of the autocollimator in S324 and the target position does not meet the requirement, S324 is repeated for the same cushion column until the distance between the echo of the autocollimator and the target position meets the requirement, and then the next cushion column that needs to be ground is ground through S324.

7. The method for precise adjustment of the optical path for long-distance laser target tracking and ranging according to claim 6 is characterized in that: The grinding amount Δl of a pad column of the second reflector that needs to be ground for the i-th time 2i The calculation formula is: Among them, d 2i H is the change in the image return angle on the autocollimator caused by the i-th tightening adjustment of a certain support column of the second reflector; 2j is the height of the pad column.

8. The method for precise adjustment of the optical path of long-distance laser target tracking and ranging according to claim 2 is characterized in that: The step of adjusting the first reflector (2) comprises: A measuring camera (84) is fixedly installed at the light-emitting end of the pitch axis; A central attenuation plate (83) is installed between the measuring camera (84) and the pitch axis (62); A first reflector (2) is mounted directly below the azimuth axis through a mounting bracket for the first reflector, and a laser (1) is mounted, wherein light emitted by the laser serves as incident light for the first reflector; Keep the turntable pitch axis stationary, rotate the turntable azimuth axis, and adjust the thickness of the pad column included in the mounting bracket of the first reflector until the change in the centroid position of the spot formed by the laser 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.

9. The method for precise adjustment of the optical path of long-distance laser target tracking and ranging according to claim 1, characterized in that: The step of adjusting the third reflector (4) comprises: The third reflector (4) and the multi-mode receiving optical system (5) are mounted together, and the autocollimator (81) is set in front of the secondary mirror (52) of the multi-mode receiving optical system and the field of view of the visible light camera (53), the autocollimator (81) self-collimates the outer end surface of the secondary mirror (52), and the posture of the autocollimator (81) is adjusted so that the image is reflected to the zero point of the autocollimator; then, the visible light camera (53) is turned on and powered on, so that the crosshairs of the autocollimator (81) are imaged in the visible light camera (53), and the position of the crosshairs in the measurement coordinate system of the visible light camera (53) is recorded, and this position is the zero point of the visible light camera; The measuring camera is placed in the light emitting direction of the third reflector (4), and an attenuation plate (85) is installed between the light emitting direction of the third reflector (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 pass through the corner reflector and form an image in the measuring camera (84); finally, the laser is powered on, so that the laser output light is reflected by the third reflector (4), and is formed in the measuring camera after being attenuated by the attenuation plate (85), and the position coordinates (X0, X0) of the image of the crosshairs of the autocollimator (81) in the measuring camera (84) are recorded, and this position is the projection position of the zero point of the visible light camera in the measuring camera; The three pads included in the mounting bracket of the third reflector are adjusted until the deviation between the image of the autocollimator cross 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.

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