A multi-channel laser beam combining optical axis and rotary table rotation coaxial calibration system and method

Abstract

The present application relates to laser turntable calibration technical field, specifically relates to a kind of multi-channel laser beam combination optical axis and turntable rotation coaxial calibration system and method, multi-channel laser beam combination optical axis and turntable rotation coaxial calibration system includes beam combination system and turntable system, the laser emitted by multiple lasers in beam combination system is controlled light-emitting angle by corresponding two-dimensional swing mirror and is reflected to beam combination lens group, and multi-beam laser is transmitted to first Kude two-dimensional swing mirror after beam combination by beam combination lens group, and first Kude two-dimensional swing mirror reflects beam combination laser to turntable system;Beam combination laser is reflected to beam splitter in turntable system by Kude lens group, and beam splitter divides beam combination laser into two beams, one laser is emitted to far field, and another laser is incident to optical axis monitoring unit, and optical axis monitoring unit detects laser spot centroid position in real time.The present application can realize high-precision, dynamic stable coaxial calibration under single tooling, minimum disassembly condition, effectively solve the problem of multi-path cooperation and long-period pointing stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser turntable calibration technology, and particularly relates to a multi-channel laser beam axis and turntable rotation coaxial calibration system and method. BACKGROUND

[0002] With the development of photoelectric reconnaissance and guidance technology towards multi-band fusion, the photoelectric countermeasure system has increasingly higher requirements for the working wavelength and power of the laser. Multi-channel lasers of different wavelengths are combined to realize the coaxial output of multi-wavelength and high-power laser, which has become the mainstream technology in the field. However, the spatial coincidence degree of the laser beam axis after the combination and the rotation axis of the turntable directly affects the pointing accuracy and countermeasure effect of the system. The current technical bottleneck is that the pointing deviation caused by the optical axis drift after the combination of multi-channel lasers, the mechanical shaft system error and the environmental disturbance cannot be satisfied with the high-precision calibration requirement under the multi-axis constraint condition by the traditional calibration method. In the prior art, the mechanical calibration method depends on the standard ball or calibration plate to establish a coordinate system, but is limited in applicability due to the limitation of the depth of field of the profilometer and the need to expose the internal parameter interface; the optical calibration method has high accuracy, but is usually designed for a single path and lacks the ability of multi-path collaborative calibration. In addition, factors such as the thermal effect of the laser, mechanical vibration and gravity deformation will introduce micron-level displacement or arcsecond-level angle deviation, which will cause significant error in long-distance application. Therefore, there is an urgent need for a system and method for realizing the coaxial calibration of the multi-channel laser beam axis and the rotation axis of the turntable under the condition of a single tool and minimum disassembly. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to overcome the defects in the prior art, so as to provide a multi-channel laser beam axis and turntable rotation coaxial calibration system and method.

[0004] A multi-channel laser beam axis and turntable rotation coaxial calibration system, comprising a combination system and a turntable system;

[0005] The combination system comprises a plurality of lasers of different wavelengths, a plurality of two-dimensional galvanometer mirrors arranged corresponding to the light outlets of the lasers, a combination mirror group and a first Kothmann two-dimensional galvanometer mirror; the lasers emitted by the plurality of lasers control the light emitting angle through the corresponding two-dimensional galvanometer mirrors and reflect the lasers to the combination mirror group, and the combined lasers are transmitted to the first Kothmann two-dimensional galvanometer mirror after being combined by the combination mirror group, and the first Kothmann two-dimensional galvanometer mirror reflects the combined lasers to the turntable system;

[0006] The turntable system comprises a turntable body and an optical axis monitoring unit, a beam splitter and a Kothmann mirror group arranged on the turntable body; the combined lasers are reflected to the beam splitter by the Kothmann mirror group, the beam splitter divides the combined lasers into two beams, one beam of laser is emitted to the far field, and the other beam of laser is incident to the optical axis monitoring unit, and the optical axis monitoring unit detects the centroid position of the laser spot in real time.

[0007] Further, the Kotha mirror group comprises a second Kotha two-dimensional swing mirror, a second Kotha mirror and a first Kotha mirror, and the combined laser is reflected to the beam splitter in sequence through the first Kotha mirror, the second Kotha mirror and the second Kotha two-dimensional swing mirror.

[0008] Further, the combined box is further included; the combined system and the turntable system are installed on the combined box, and the flatness of the installation surface of the combined box is less than 0.1 mm, and the parallelism is less than 5".

[0009] Further, the multiple waveband different lasers comprise a first laser, a second laser, a third laser, a fourth laser and a fifth laser, and a first two-dimensional swing mirror, a second two-dimensional swing mirror, a third two-dimensional swing mirror, a fourth two-dimensional swing mirror and a fifth two-dimensional swing mirror are correspondingly arranged at light outlets of the first laser, the second laser, the third laser, the fourth laser and the fifth laser; a first combined mirror corresponds to positions of the first two-dimensional swing mirror and the second two-dimensional swing mirror, a second combined mirror corresponds to a position of the third two-dimensional swing mirror, a third combined mirror corresponds to a position of the fourth two-dimensional swing mirror, and a fourth combined mirror corresponds to positions of the fifth two-dimensional swing mirror and the first Kotha two-dimensional swing mirror.

[0010] A method for calibrating the coaxiality of the optical axis of a multi-channel laser beam combination and the rotation of a turntable, which is based on the multi-channel laser beam combination optical axis and turntable rotation coaxiality calibration system described above, and comprises the following steps:

[0011] S1: calibrating the multi-channel laser beam combination optical path;

[0012] S2: calibrating the coaxiality of the optical axis of the combined laser and the rotation axis of the turntable;

[0013] S3: real-time compensation adjustment.

[0014] Further, the step S1 specifically comprises the following steps:

[0015] S1.1: fix the azimuth position and the pitch position of the turntable body, turn on the first laser to emit laser, and part of the laser passes through the beam splitter into the optical axis monitoring unit after passing through the combined mirror group, the first Kotha two-dimensional swing mirror and the Kotha mirror group, the optical axis monitoring unit detects the position of the laser spot centroid in real time, adjusts the position of the first laser emitted laser on the optical axis monitoring unit to (X0, Y0) through the first two-dimensional swing mirror, and records the position, (X0, Y0) is the center theoretical position of the optical axis monitoring unit, which is set as (0, 0);

[0016] S1.2: Turn off the first laser and turn on the second laser to emit laser light. After passing through the beam combiner group, the first Couder 2D oscillating mirror, and the Couder mirror group, part of the laser light passes through the beam splitter and enters the optical axis monitoring unit. Read the position information of the laser light in the optical axis monitoring unit, and adjust the second 2D oscillating mirror to adjust the position of the laser light emitted by the second laser light in the optical axis monitoring unit to (X0, Y0). The laser beam combining optical path calibration of the first laser and the second laser light is completed.

[0017] S1.3: Based on the same principle, adjust the third, fourth, and fifth two-dimensional mirrors in sequence to adjust the positions of the lasers emitted by the third, fourth, and fifth lasers in the optical axis monitoring unit to (X0, Y0), thus completing the calibration of the multi-path laser beam combining optical path.

[0018] Furthermore, step S2 specifically includes the following steps:

[0019] S2.1: Turn on all lasers. After the combined laser beam passes through the first Couder 2D mirror, it enters the interior of the turntable body. First, fix the pitch rotation axis of the turntable body, rotate the azimuth rotation axis to any position, and record the initial position (X1, Y1) of the combined laser beam in the optical axis monitoring unit. At this time, the position is calibrated as 0°.

[0020] S2.2: Adjust the turntable body to rotate around the azimuth rotation axis by 90°, 180° and 270° in sequence, and record the position of the combined laser beam in the optical axis monitoring unit (X2,Y2), (X3,Y3) and (X4,Y4) respectively.

[0021] S2.3: Determine the center position (X5,Y5) using (X1,Y1), (X2,Y2), (X3,Y3), and (X4,Y4). After adjusting the first Kuder two-dimensional pendulum mirror to rotate the turntable body around the azimuth rotation axis, the spot of the combined laser beam will always be located at the position (X5,Y5) in the optical axis monitoring unit. At this time, the azimuth rotation axis and the optical axis of the combined laser beam are calibrated.

[0022] S2.4: Fix the azimuth rotation axis, rotate the pitch rotation axis to any position, and record the initial position (X6, Y6) of the combined laser in the optical axis monitoring unit. At this time, the position is calibrated as 0°.

[0023] S2.5: Adjust the turntable body to rotate around the pitch axis by 90°, 180° and 270° in sequence, and record the position of the combined laser beam in the optical axis monitoring unit (17) (X7,Y7), (X8,Y8) and (X9,Y9) respectively.

[0024] S2.6: Determine the center (X6,Y6), (X7,Y7), (X8,Y8), and (X9,Y9) of the circle. 10 ,Y 10), after the rotation of the rotation table body around the pitch rotation axis by adjusting the second KODAK two-dimensional swing mirror, the spot of the combined laser is always located at the position of the optical axis monitoring unit (X 10 ,Y 10 ), at this time, the pitch rotation axis and the combined laser optical axis are calibrated.

[0025] Further, the step S3 is specifically:

[0026] Taking the position of (X 10 ,Y 10 ) as the reference origin, the data of the optical axis monitoring unit is read in real time by the central control unit, and the two-dimensional swing mirror of each laser light outlet is controlled to perform dynamic compensation, so that the positions of the multiple lasers entering the optical axis monitoring unit are stabilized at the reference origin, thereby ensuring that the combined laser optical axis is coaxial with the rotation axis of the rotation table in real time.

[0027] Further, the real-time reading of the data of the optical axis monitoring unit and the dynamic compensation of the two-dimensional swing mirror of each laser light outlet specifically includes the following steps:

[0028] S3.1: Real-time monitoring and reading the position data (X t ,Y t ) of the spot centroid in the optical axis monitoring unit;

[0029] S3.2: Calculate the offset ΔX and ΔY of (X t ,Y t ) and the reference origin (X 10 ,Y 10 ), ΔX=X t -X 10 , ΔY=Y t -Y 10 ;

[0030] S3.3: Determine whether the offset ΔX and ΔY exceed the preset threshold;

[0031] S3.4: If the offset ΔX and ΔY exceed the preset threshold, generate a control instruction by a PID algorithm to drive the pitch angle δ j and the azimuth angle δ γ of the corresponding two-dimensional swing mirror to correct the pointing of the laser beam, and return to step S3.1;

[0032] If the offset ΔX and ΔY do not exceed the threshold, the current state is maintained, and step S3.1 is returned to continue monitoring.

[0033] Further, the method further includes step 4: based on the shaft system deviation solution, the mechanical components in the combined mirror group are corrected; the specific steps are:

[0034] S4.1: the curves of the offset amount ΔX and ΔY and the rotation angle θ of the turntable body ΔX-θ and ΔY-θ are fitted, if the curve presents a sine or cosine law, the amplitude A reflects the angle α between the combined laser and the rotation shaft, wherein α≈A / (2L), L is the distance from the optical axis monitoring unit to the rotation center of the turntable body; at the same time, the spatial translation offset amount of the combined laser and the rotation shaft is determined by analyzing the direct current component of the curve;

[0035] S4.2: based on the angle α and the translation offset amount obtained in step S4.1, the corresponding mechanical parts in the combined laser group are adjusted;

[0036] S4.3: whether the maximum offset amount of the light spot satisfies the system index is measured by rotating the azimuth rotation shaft and the pitch rotation shaft respectively, if not, return to step S4.2 until the maximum offset amount of the light spot satisfies the system index.

[0037] The beneficial effects of the present application are:

[0038] 1. By setting a two-dimensional swing mirror at the outlet of each laser and calibrating each path with the same reference point of the optical axis monitoring unit, the spatial coincidence of multiple lasers before combination is ensured, laying a foundation for subsequent calibration.

[0039] 2. The method of four-point determination of the center of a circle is used to calibrate the rotation centers of the azimuth rotation shaft and the pitch rotation shaft respectively, and the optical axis is made to coincide with the mechanical shaft by adjusting the corresponding Kude two-dimensional swing mirror, which is intuitive, efficient and high in precision.

[0040] 3. The light spot position is monitored in real time by the optical axis monitoring unit, and the two-dimensional swing mirror is driven by the central control unit through the PID algorithm for closed-loop correction, effectively compensating for the pointing drift caused by environmental disturbance, mechanical deformation and other factors, and ensuring the long-term coaxial stability of the system during operation.

[0041] 4. By analyzing the relationship curve of the light spot offset amount and the rotation angle of the turntable, the angular deviation and positional deviation of the optical axis and the rotation shaft can be calculated, and the pitch, yaw or lateral mechanical fine adjustment of the combiner base is guided accordingly, which corrects the systematic installation error from the root.

[0042] 5. The multi-laser combined optical axis and turntable rotation coaxial calibration system of the present application is highly integrated, the combined system and the turntable system are installed on the same combined box, and the calibration process is completed based on the built-in optical axis monitoring unit and the multiple electrically controllable two-dimensional swing mirrors and Kude two-dimensional swing mirrors in the system, without relying on external complex calibration equipment or frequent disassembly of the system, which significantly simplifies the operation process, reduces the dependence on personnel experience, and effectively avoids the repetitive errors introduced by multiple disassembly and assembly. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0044] Figure 1 Figure 1 is a schematic diagram of the optical path of a multi-channel laser beam combining coaxial alignment system with a rotary table;

[0045] Figure 2 Figure 2 is a schematic diagram of a beam combining system;

[0046] Figure 3 Figure 3 is a schematic diagram of a rotary table system;

[0047] Figure 4 Figure 4 is a schematic diagram of determining (X5, Y5) in an optical axis monitoring unit;

[0048] Figure 5 Figure 5 is a flowchart of real-time compensation adjustment.

[0049] Legend of reference signs:

[0050] 1 - beam combining box; 2 - first laser; 3 - first two-dimensional swing mirror;

[0051] 4 - second laser; 5 - second two-dimensional swing mirror; 6 - third laser;

[0052] 7 - third two-dimensional swing mirror; 8 - fourth laser; 9 - fourth two-dimensional swing mirror;

[0053] 10 - fifth laser; 11 - fifth two-dimensional swing mirror; 12 - first Kude two-dimensional swing mirror;

[0054] 13 - fourth beam combining mirror; 14 - third beam combining mirror; 15 - second beam combining mirror;

[0055] 16 - first beam combining mirror; 17 - optical axis monitoring unit; 18 - beam splitter;

[0056] 19 - second Kude two-dimensional swing mirror; 20 - second Kude mirror; 21 - first Kude mirror;

[0057] 22 - azimuth rotation axis; 23 - rotary table body; 24 - pitch rotation axis. DETAILED DESCRIPTION

[0058] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0059] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0060] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0061] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0062] Please refer to Figures 1 to 3 A multi-channel laser beam combining optical axis and rotary table rotation coaxial calibration system, comprising a beam combining system and a rotary table system;

[0063] The beam combining system comprises a plurality of lasers with different wavebands, a plurality of two-dimensional galvanometer mirrors arranged corresponding to the light outlets of the lasers, a beam combining mirror group, and a first Kude two-dimensional galvanometer mirror 12. The lasers emitted by the plurality of lasers control the light emitting angle through the corresponding two-dimensional galvanometer mirrors and reflect the lasers to the beam combining mirror group. After the multi-beam lasers are combined by the beam combining mirror group, they are transmitted to the first Kude two-dimensional galvanometer mirror 12. The first Kude two-dimensional galvanometer mirror 12 reflects the combined laser to the rotary table system.

[0064] The turntable system comprises a turntable body 23 and a light axis monitoring unit 17, a beam splitter 18 and a coude mirror group arranged on the turntable body 23; the turntable body 23 mainly performs azimuth and pitch rotary motion and carries various mirror groups and loads, and the coude mirror group mainly reflects the laser introduced by the beam combining system after the azimuth and pitch motion; the combined laser is reflected to the beam splitter 18 through the coude mirror group, the beam splitter 18 divides the combined laser into two beams, one of which is emitted to the far field, and the other of which is incident to the light axis monitoring unit 17, which detects the laser spot centroid position in real time, i.e. (X, Y) coordinates, for directly feeding back the pointing deviation of the combined laser.

[0065] The coude mirror group comprises a second coude two-dimensional swing mirror 19, a second coude mirror 20 and a first coude mirror 21, and the combined laser is reflected to the beam splitter 18 in sequence through the first coude mirror 21, the second coude mirror 20 and the second coude two-dimensional swing mirror 19.

[0066] The multi-channel laser beam combining light axis and turntable rotation coaxial calibration system further comprises that the beam combining box body 1 is made of low thermal deformation material; the beam combining system and the turntable system are both mounted on the beam combining box body 1, and an optical mounting surface of the beam combining box body 1 is precisely ground to meet the technical requirements of a flatness of <0.1 mm and a parallelism of <5'', thereby providing a stable mounting reference for optical components.

[0067] The multiple waveband different lasers comprise a first laser 2, a second laser 4, a third laser 6, a fourth laser 8 and a fifth laser 10, and a first two-dimensional swing mirror 3, a second two-dimensional swing mirror 5, a third two-dimensional swing mirror 7, a fourth two-dimensional swing mirror 9 and a fifth two-dimensional swing mirror 11 are correspondingly arranged at light outlets of the first laser 2, the second laser 4, the third laser 6, the fourth laser 8 and the fifth laser 10; a first beam combining mirror 16 corresponds to the positions of the first two-dimensional swing mirror 3 and the second two-dimensional swing mirror 5, a second beam combining mirror 15 corresponds to the position of the third two-dimensional swing mirror 7, a third beam combining mirror 14 corresponds to the position of the fourth two-dimensional swing mirror 9, and a fourth beam combining mirror 13 corresponds to the positions of the fifth two-dimensional swing mirror 11 and the first coude two-dimensional swing mirror 12.

[0068] The application further comprises a multi-channel laser beam combining light axis and turntable rotation coaxial calibration method, which is realized based on the above-mentioned multi-channel laser beam combining light axis and turntable rotation coaxial calibration system and comprises the following steps:

[0069] S1: calibrating the multi-channel laser beam combining light path;

[0070] S2: calibrating the combined laser light axis and the turntable rotation axis;

[0071] S3: performing real-time compensation adjustment.

[0072] The step S1 specifically comprises the following steps:

[0073] S1.1: Fix the azimuth and pitch positions of the turntable body 23, turn on the first laser 2 to emit laser light, after the laser passes through the beam combiner group, the first Couder two-dimensional swing mirror 12, and the Couder mirror group, part of the laser light passes through the beam splitter 18 and enters the optical axis monitoring unit 17. The optical axis monitoring unit 17 detects the centroid position of the laser spot in real time, and adjusts the position of the laser emitted by the first laser 2 on the optical axis monitoring unit 17 to (X0,Y0) by adjusting the first two-dimensional swing mirror 3, and records this position. (X0,Y0) is the theoretical center position of the optical axis monitoring unit 17, set as (0,0).

[0074] S1.2: Turn off the first laser 2, turn on the second laser 4 to emit laser. After the laser passes through the beam combiner group, the first Couder two-dimensional swing mirror 12, and the Couder mirror group, part of the laser passes through the beam splitter 18 and enters the optical axis monitoring unit 17. Read the position information of the laser in the optical axis monitoring unit 17, and adjust the second two-dimensional swing mirror 5 to adjust the position of the laser emitted by the second laser 4 in the optical axis monitoring unit 17 to X0, Y0. The laser beam combining optical path calibration of the first laser 2 and the second laser 4 is completed.

[0075] S1.3: Based on the same principle, adjust the third two-dimensional mirror 7, the fourth two-dimensional mirror 9, and the fifth two-dimensional mirror 11 in sequence to adjust the position of the laser emitted from the third laser 6, the fourth laser 8, and the fifth laser 10 in the optical axis monitoring unit 17 to X0, Y0, thus completing the calibration of the multi-path laser beam combining optical path.

[0076] Step S2 specifically includes the following steps:

[0077] S2.1: Turn on all lasers. After the combined laser beam passes through the first Kuder two-dimensional swing mirror 12, it enters the interior of the turntable body 23. First, fix the pitch rotation axis 24 of the turntable body 23, rotate the azimuth rotation axis 22 to any position, and record the initial position (X1, Y1) of the combined laser beam in the optical axis monitoring unit 17. At this time, the position is calibrated as 0°.

[0078] S2.2: Rotate the turntable body 23 around the azimuth rotation axis 22 by 90°, 180° and 270° in sequence, and record the position of the combined laser beam in the optical axis monitoring unit 17 (X2,Y2), (X3,Y3) and (X4,Y4) respectively.

[0079] S2.3: such as Figure 4 As shown, the center position (X5,Y5) is determined by (X1,Y1), (X2,Y2), (X3,Y3) and (X4,Y4). After the turntable body 23 rotates around the azimuth rotation axis 22 by adjusting the first Kuder two-dimensional swing mirror 12, the spot of the combined laser beam is always located at the position (X5,Y5) in the optical axis monitoring unit 17. At this time, the azimuth rotation axis 22 and the optical axis of the combined laser beam are calibrated.

[0080] S2.4: Fix the azimuth rotation axis 22, rotate the pitch rotation axis 24 to any position, and record the initial position (X6, Y6) of the combined laser in the optical axis monitoring unit 17. At this time, the position is calibrated as 0°.

[0081] S2.5: Adjust the turntable body 23 to rotate around the pitch and rotation axis 24 by 90°, 180° and 270° in sequence, and record the position of the combined laser beam in the optical axis monitoring unit 17 (X7,Y7), (X8,Y8) and (X9,Y9) respectively.

[0082] S2.6: Determine the center (X6,Y6), (X7,Y7), (X8,Y8), and (X9,Y9) of the circle. 10 ,Y 10 By adjusting the second Kuder two-dimensional pendulum mirror 19 to rotate the turntable body 23 around the pitch axis 24, the spot of the combined laser beam remains in the optical axis monitoring unit 17 (X). 10 ,Y 10 At this position, the pitch rotation axis 24 and the beam-combining laser optical axis calibration are completed.

[0083] Step S3 specifically involves:

[0084] (X) 10 ,Y 10 The central control unit reads the data from the optical axis monitoring unit 17 in real time, using the position as the reference origin, and controls the two-dimensional mirrors of each laser output port to perform dynamic compensation, so that the position of the multiple lasers entering the optical axis monitoring unit 17 is stabilized at the reference origin, thereby ensuring that the optical axis of the combined laser beam is coaxial with the rotation axis of the turntable in real time.

[0085] like Figure 5 As shown, the real-time reading of data from the optical axis monitoring unit 17 and the control of the two-dimensional tilting mirrors at each laser output port for dynamic compensation specifically include the following steps:

[0086] S3.1: Real-time monitoring and reading of the spot centroid position data (X) in the optical axis monitoring unit 17. t ,Y t );

[0087] S3.2: Calculate (X) t ,Y t ) and the reference origin (X) 10 ,Y 10 The offsets ΔX and ΔY, where ΔX = X t -X 10 ΔY=Y t -Y 10 ;

[0088] S3.3: judging whether the offset ΔX and ΔY exceed the preset threshold value;

[0089] S3.4: if the offset ΔX and ΔY exceed the preset threshold value, generating a control instruction by a PID algorithm to drive the pitch angle δ of the corresponding two-dimensional swing mirror j and the azimuth angle δ γ , performing laser beam pointing correction, and returning to step S3.1;

[0090] If the offset ΔX and ΔY do not exceed the threshold value, the current state is maintained, and the step S3.1 is returned to continue monitoring.

[0091] The method further comprises a step 4: based on the shaft deviation solution, correcting the mechanical components in the beam combination mirror group; the specific steps are:

[0092] S4.1: fitting the curves ΔX-θ and ΔY-θ of the offset ΔX and ΔY and the rotation angle θ of the turntable body 23, specifically including the curves ΔX-θ1 and ΔY-θ1 of the offset ΔX and ΔY and the rotation angle θ1 of the azimuth rotation axis 22, and the curves ΔX-θ2 and ΔY-θ2 of the offset ΔX and ΔY and the rotation angle θ2 of the pitch rotation axis 24; when it is found that the curve presents a sine or cosine law during the solution, the amplitude A reflects the included angle α between the combined laser and the rotation axis, where α≈A / (2L), L is the distance from the optical axis monitoring unit 17 to the rotation center of the turntable body 23; at the same time, the translation offset of the combined laser and the rotation axis in space is determined by analyzing the direct current component of the curve;

[0093] S4.2: based on the included angle α and the translation offset obtained in step S4.1, adjusting the corresponding mechanical components in the beam combination mirror group; when the sine or cosine law is presented, the pitch or yaw of the beam combination mirror is adjusted, and for the direct current component of the curve, the transverse position of the beam combination mirror is adjusted, and the large deviation is preferentially corrected;

[0094] S4.3: respectively rotating the azimuth rotation axis 22 and the pitch rotation axis 24 to measure whether the maximum offset of the light spot meets the system index, if not, returning to step S4.2 until the maximum offset of the light spot meets the system index(≤5μm@10m).

[0095] Obviously, the above embodiments are only examples for clear illustration, and are not a limitation on the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for calibrating the coaxiality of the optical axis of a multi-channel laser beam combiner with the rotation of a turntable, characterized in that, The method is based on a multi-channel laser beam combining optical axis and a rotary table rotation coaxial calibration system, which includes a beam combining system and a rotary table system. The beam combining system includes multiple lasers with different wavelengths, multiple two-dimensional mirrors corresponding to the laser output ports, a beam combining mirror group, and a first Couder two-dimensional mirror (12). The lasers emitted by the multiple lasers are controlled by the corresponding two-dimensional mirrors to control the output angle and reflect the lasers to the beam combining mirror group. The multiple laser beams are combined by the beam combining mirror group and transmitted to the first Couder two-dimensional mirror (12). The first Couder two-dimensional mirror (12) reflects the combined laser beam to the turntable system. The turntable system includes a turntable body (23) and an optical axis monitoring unit (17), a beam splitter (18) and a Couder mirror group disposed on the turntable body (23); the combined laser beam is reflected by the Couder mirror group to the beam splitter (18), the beam splitter (18) splits the combined laser beam into two beams, one beam is emitted to the far field, and the other beam is incident on the optical axis monitoring unit (17), the optical axis monitoring unit (17) detects the position of the centroid of the laser spot in real time; The Couder mirror group includes a second Couder two-dimensional pendulum mirror (19), a second Couder mirror (20), and a first Couder mirror (21). The combined laser beam is reflected sequentially through the first Couder mirror (21), the second Couder mirror (20), and the second Couder two-dimensional pendulum mirror (19) to the beam splitter mirror (18). The lasers with different wavelengths include a first laser (2), a second laser (4), a third laser (6), a fourth laser (8), and a fifth laser (10). The output ports of the first laser (2), the second laser (4), the third laser (6), the fourth laser (8), and the fifth laser (10) are respectively provided with a first two-dimensional oscillating mirror (3), a second two-dimensional oscillating mirror (5), a third two-dimensional oscillating mirror (7), a fourth two-dimensional oscillating mirror (9), and a fifth two-dimensional oscillating mirror (11). The first beam combiner (16) corresponds to the positions of the first two-dimensional oscillating mirror (3) and the second two-dimensional oscillating mirror (5), the second beam combiner (15) corresponds to the position of the third two-dimensional oscillating mirror (7), the third beam combiner (14) corresponds to the position of the fourth two-dimensional oscillating mirror (9), and the fourth beam combiner (13) corresponds to the position of the fifth two-dimensional oscillating mirror (11) and the first Kuder two-dimensional oscillating mirror (12). The method includes the following steps: S1: Perform calibration of the multi-path laser beam combining optical path; S2: Perform calibration of the beam combining laser optical axis and the turntable rotation axis; S3: Perform real-time compensation adjustments.

2. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 1, characterized in that, It also includes a bundle assembly box (1); the bundle assembly system and the turntable system are both installed on the bundle assembly box (1), and the flatness of the mounting surface of the bundle assembly box (1) is <0.1mm and the parallelism is <5″.

3. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 1, characterized in that, Step S1 specifically includes the following steps: S1.1: Fix the azimuth and pitch positions of the turntable body (23), turn on the first laser (2) to emit laser light, after the laser passes through the beam combiner group, the first Couder two-dimensional swing mirror (12), and the Couder mirror group, part of the laser light passes through the beam splitter (18) and enters the optical axis monitoring unit (17). The optical axis monitoring unit (17) detects the centroid position of the laser spot in real time. By adjusting the first two-dimensional swing mirror (3), the position of the laser emitted by the first laser (2) on the optical axis monitoring unit (17) is adjusted to (X0,Y0), and this position is recorded. (X0,Y0) is the theoretical center position of the optical axis monitoring unit (17), which is set to (0,0). S1.2: Turn off the first laser (2), turn on the second laser (4) to emit laser. After passing through the beam combiner group, the first Couder two-dimensional swing mirror (12), and the Couder mirror group, part of the laser passes through the beam splitter (18) and enters the optical axis monitoring unit (17). Read the position information of the laser in the optical axis monitoring unit (17), and adjust the second two-dimensional swing mirror (5) to adjust the position of the laser emitted by the second laser (4) in the optical axis monitoring unit (17) to (X0,Y0). The laser beam combining optical path calibration of the first laser (2) and the second laser (4) is completed. S1.3: Based on the same principle, adjust the third two-dimensional mirror (7), the fourth two-dimensional mirror (9), and the fifth two-dimensional mirror (11) in sequence to adjust the position of the laser emitted by the third laser (6), the fourth laser (8), and the fifth laser (10) in the optical axis monitoring unit (17) to (X0,Y0), and complete the calibration of the multi-path laser beam combining optical path.

4. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 3, characterized in that, Step S2 specifically includes the following steps: S2.1: Turn on all lasers. After the combined laser beam passes through the first Couder 2D pendulum mirror (12), it enters the interior of the turntable body (23). First, fix the pitch rotation axis (24) of the turntable body (23), rotate the azimuth rotation axis (22) to any position, and record the initial position (X1,Y1) of the combined laser beam in the optical axis monitoring unit (17). At this time, the position is calibrated as 0°. S2.2: Adjust the turntable body (23) to rotate 90°, 180° and 270° around the azimuth rotation axis (22) in sequence, and record the position of the combined laser beam in the optical axis monitoring unit (17) (X2,Y2), (X3,Y3) and (X4,Y4) respectively. S2.3: Determine the center position (X5,Y5) by (X1,Y1), (X2,Y2), (X3,Y3) and (X4,Y4). After the turntable body (23) rotates around the azimuth rotation axis (22) by adjusting the first Kuder two-dimensional swing mirror (12), the spot of the combined laser beam is always located at the position (X5,Y5) in the optical axis monitoring unit (17). At this time, the azimuth rotation axis (22) and the optical axis of the combined laser beam are calibrated. S2.4: Fix the azimuth rotation axis (22), rotate the pitch rotation axis (24) to any position, and record the initial position (X6, Y6) of the combined laser in the optical axis monitoring unit (17). At this time, the position is calibrated as 0°. S2.5: Adjust the turntable body (23) to rotate around the pitch rotation axis (24) by 90°, 180° and 270° in sequence, and record the position of the combined laser beam in the optical axis monitoring unit (17) (X7,Y7), (X8,Y8) and (X9,Y9) respectively. S2.6: Determine the center (X6,Y6), (X7,Y7), (X8,Y8), and (X9,Y9) of the circle. 10 ,Y 10 By adjusting the second Couder two-dimensional pendulum mirror (19) to rotate the turntable body (23) around the pitch rotation axis (24), the spot of the combined laser beam is always located in the optical axis monitoring unit (17) (X). 10 ,Y 10 At the position, the pitch rotation axis (24) and the beam-combining laser optical axis are calibrated.

5. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 4, characterized in that, Step S3 specifically involves: (X) 10 ,Y 10 The central control unit reads the data from the optical axis monitoring unit (17) in real time and controls the two-dimensional mirrors of each laser output port to perform dynamic compensation, so that the position of the multiple lasers entering the optical axis monitoring unit (17) is stable at the reference origin, thereby ensuring that the optical axis of the combined laser beam is coaxial with the rotation axis of the turntable in real time.

6. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 5, characterized in that, The process of reading data from the optical axis monitoring unit (17) in real time and controlling the two-dimensional mirrors at each laser output port to perform dynamic compensation specifically includes the following steps: S3.1: Real-time monitoring and reading of the spot centroid position data (X) in the optical axis monitoring unit (17) t ,Y t ); S3.2: Calculate (X) t ,Y t ) and the reference origin (X) 10 ,Y 10 The offsets ΔX and ΔY, where ΔX = X t -X 10 ΔY=Y t -Y 10 ; S3.3: Determine whether the offsets ΔX and ΔY exceed the preset thresholds; S3.4: If the offsets ΔX and ΔY exceed the preset thresholds, a control command is generated using a PID algorithm to drive the pitch angle δ of the corresponding two-dimensional pendulum mirror. j and azimuth angle δ γ Perform laser beam pointing correction and return to step S3.1; If the offsets ΔX and ΔY do not exceed the threshold, maintain the current state and return to step S3.1 to continue monitoring.

7. The method for calibrating the coaxiality of the multi-channel laser beam combining optical axis and the turntable rotation according to claim 6, characterized in that, The method further includes step 4: correcting the mechanical components in the beam combiner assembly based on axis deviation calculation; the specific steps are as follows: S4.1: Fit the curves ΔX-θ and ΔY-θ of the offset ΔX and ΔY with the rotation angle θ of the turntable body (23). If the curves show a sine or cosine pattern, then its amplitude A reflects the angle α between the combined laser and the rotating axis, where α≈A / (2L), and L is the distance from the optical axis monitoring unit (17) to the rotation center of the turntable body (23). At the same time, by analyzing the DC component of the curve, determine the translational offset of the combined laser and the rotating axis in space. S4.2: Adjust the corresponding mechanical components in the beam combiner assembly based on the included angle α and translation offset obtained in step S4.1; S4.3: Rotate the azimuth axis (22) and the pitch axis (24) respectively to measure whether the maximum offset of the light spot meets the system index. If it does not meet the index, return to step S4.2 until the maximum offset of the light spot meets the system index.

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