Accurate assembly method and system of laser interferometer micro-probe sensor

Abstract

The invention relates to a precise assembly method and system for a laser interferometer micro-probe sensor, and solves the problem that automatic, rapid and precise assembly between a spectroscope and a collimating lens in the laser interferometer micro-probe sensor is difficult to realize. The method comprises the steps of alignment of the beam splitter prism and the collimating lens, dispensing, curing, clamping and releasing. Based on visual feedback information and optical feedback information, alignment of positions and postures between the beam splitter prism and the collimating lens is realized; then, accurately quantitative glue is applied between the beam splitter prism and the collimating lens through glue dispensing and curing, the assembly force for connection between the beam splitter prism and the collimating lens is controlled through clamping and releasing, and connection between the beam splitter prism and the collimating lens is achieved through irradiation of a curing device. The system comprises a clamp, a plane mirror, a clamp holder, a rotating platform, a translation table, a visual device, a controller, a box body and the like, visual feedback information and optical feedback information are obtained through the controller, the actuator is controlled to move, and rapid and precise alignment and assembly are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro optical element assembly, and particularly relates to a precise assembly method and system of a laser interferometer micro probe sensor. BACKGROUND

[0002] Optical micro probe sensors have a wide range of applications in precision engineering and high-end equipment due to their small size, easy assembly and easy implementation of embedded measurement. In optical micro probe sensors, the assembly quality of the sensitive core micro optical element directly affects the sensing accuracy and performance, and therefore high precision assembly is required.

[0003] To achieve precise assembly of the micro probe sensor, three key issues need to be addressed. First, the precise alignment of the beam splitter prism and the collimating lens in position and attitude needs to be achieved to ensure that the reflected light of the beam splitter prism coated with a reflective film layer can return to the optical fiber. Second, stable clamping and precise release of the beam splitter prism need to be achieved, and the assembly force between the micro beam splitter prism and the collimating lens needs to be monitored in real time to avoid changes in the relative position and attitude caused by unstable clamping or unbalanced release. Third, stable connection between the two is ensured through dispensing and curing operations, and at the same time, changes in the relative attitude relationship and the light path propagation characteristics of the two are reduced. SUMMARY

[0004] The present application provides a precise assembly method and system of a laser interferometer micro probe sensor, which solves the problem of difficult automatic, rapid and precise alignment and assembly between the beam splitter and the collimating lens in the laser interferometer micro probe sensor.

[0005] The technical solution of the present application is as follows:

[0006] A precise assembly system of a laser interferometer micro probe sensor, comprising: a box body, a laser, a circulator, a photodetector and a controller;

[0007] A plane mirror is assembled on the table top of the box body through a first rotating platform;

[0008] A first optical element is assembled on the table top of the box body through a second rotating platform, and the first optical element is arranged below the plane mirror;

[0009] A second optical element is assembled on the table top of the box body through a clamp, and the second optical element is arranged below the first optical element, and the upper surface of the clamp serves as an imaging screen for the reflected light of the plane mirror;

[0010] A dispensing device is clamped by a first clamp, and the first clamp is assembled on the table top of the box body through a first translation table;

[0011] a curing device, which is assembled on the table top of the box through a second translation stage;

[0012] a side-view imaging device, which is assembled on the table top of the box;

[0013] a visual feedback device, which is assembled on the table top of the box;

[0014] the output of the laser is connected to the second optical element through a circulator, the other output of the circulator is connected to the photodetector, and the output of the photodetector is connected to the controller;

[0015] the input of the controller is connected to the visual feedback device, and the output is connected to the first rotation platform, the second rotation platform, the first translation stage and the second translation stage;

[0016] the center of the plane mirror coincides with the rotation center of the first rotation platform;

[0017] the center of the first optical element coincides with the rotation center of the second rotation platform;

[0018] the rotation center of the first rotation platform, the rotation center of the second rotation platform and the central axis of the clamp are arranged on the same axis;

[0019] the side-view imaging device is arranged in parallel with the axis.

[0020] Preferably, the controller controls the first rotation platform and the second rotation platform through the visual feedback of the visual feedback device and the optical feedback of the photodetector, so as to realize the alignment of the position and posture of the second optical element and the first optical element;

[0021] After the alignment of the position and posture of the second optical element and the first optical element is completed, the dispensing device generates a precise amount of glue, and the glue is applied between the second optical element and the first optical element through contact transfer;

[0022] After dispensing is completed, the curing device is irradiated from vertically above the connection between the second optical element and the first optical element to the bottom, so as to realize the curing connection of the second optical element and the first optical element.

[0023] Preferably, the dispensing device comprises a microsyringe, and the microsyringe is fixed on the first translation stage through a first holder;

[0024] The needle tube axis of the microsyringe is parallel to the exit end surface of the first optical element;

[0025] When dispensing, a precise amount of glue droplet is extruded by the micro-syringe and adhered to the needle tip of the micro-syringe; the controller controls the first translation table to move the needle tip of the micro-syringe to above the first optical element;

[0026] The controller also extracts the height difference between the needle tip and the upper surface of the first optical element, the horizontal position difference between the needle tip and the upper surface of the first optical element, and the glue amount information of the glue droplet from the image obtained by the visual feedback device, so as to control the first translation table to descend and translate, so that the glue droplet is in contact with the center of the upper surface of the first optical element, and the contact transfer of the glue droplet is realized.

[0027] The controller also extracts the glue amount adhered to the end surface of the first optical element from the obtained image, so as to realize precise control of the dispensing amount.

[0028] Preferably, the curing device comprises a curing device fixed on the second translation table;

[0029] The light exit surface of the curing device is downward, the axis thereof is parallel to the axis, and the movement direction of the lifting displacement table in the second translation table is coplanar with the axis.

[0030] When curing, the controller controls the second translation table to move the curing device to above the connection between the second optical element and the first optical element, and then adjusts the height of the curing device by the second translation table, so that the exit focal plane of the curing device coincides with the connection between the second optical element and the first optical element.

[0031] Preferably, the exit laser of the laser comprises working wavelength laser and visible indication laser, and the center wavelength of the photodetector is the working wavelength;

[0032] When the visual feedback is aligned, the visible indication laser provides an indication point; when the optical feedback is aligned, the photodetector detects the laser intensity of the working wavelength as an optical intensity feedback signal transmitted to the controller.

[0033] Preferably, the clamp comprises a first base, a first cover plate, and a first pivot fixing member;

[0034] The first cover plate is rotatably connected with the first base through the first pivot fixing member;

[0035] The upper surfaces of the first cover plate and the first base jointly serve as an imaging screen of the reflected light of the plane mirror;

[0036] The axis centers of the first cover plate and the first base jointly form a groove for fixing the second optical element;

[0037] The axis centers of the first cover plate and the first base jointly form a fiber passing groove, and the fiber passing groove is communicated with the groove;

[0038] The first cover plate and the first base are also attached by a first magnetic attachment.

[0039] Preferably, the first clamp includes a second base, a second cover plate and a second pivot fixing member.

[0040] The clamp cover plate is rotatably connected to the tabletop of the clamp box body by the pivot fixing member.

[0041] The second cover plate and the second base are provided with outwardly extending half hollow cylindrical structures, and the two half hollow cylindrical structures form a complete hollow cylindrical structure.

[0042] In use, the needle tube of the micro-injector is fixed in the hollow groove of the hollow cylindrical structure.

[0043] The second cover plate and the second base are also attached by a second magnetic attachment.

[0044] Preferably, the alignment process of the plane mirror includes coarse alignment and fine alignment.

[0045] The alignment process of the first optical element includes coarse alignment and fine alignment.

[0046] The step of coarse alignment of the plane mirror includes: the controller controls the second rotating platform to move the first optical element away from the second optical element to the light beam path of the plane mirror, and then controls the laser to emit light outward; the emitted light is transmitted through the optical fiber, and then the emitted light is collimated by the second optical element and reflected by the plane mirror to the imaging screen; the controller controls the first rotating platform to adjust the posture of the plane mirror according to the light spot position image on the imaging screen collected by the global vision device, so that the reflected light beam of the plane mirror is directed to the end face center of the imaging screen.

[0047] The step of fine alignment of the plane mirror includes: the controller first controls the first rotating platform to rotate to realize spiral scanning, and adjusts the tilt angle of the plane mirror; at the same time, the light intensity value of the reflected light beam of the plane mirror detected by the photoelectric detector is monitored; when the light intensity value of the reflected light beam of the plane mirror detected by the photoelectric detector is greater than a set threshold value, the first rotating platform is controlled to rotate to realize upward search scanning until the light intensity value of the reflected light beam of the plane mirror detected by the photoelectric detector reaches a maximum value.

[0048] The step of coarsely aligning the first optical element comprises: the controller controls the second rotating platform to move the first optical element into the light beam path of the second optical element and the planar mirror, and then controls the laser to emit light; the emitted light is transmitted through the optical fiber, collimated by the second optical element, and then separated into reference light and measurement light by the first optical element; the reference light is reflected by the planar mirror to form a first light spot on the side-view imaging device, and the measurement light forms a second light spot on the side-view imaging device; the controller controls the second rotating platform to adjust the attitude of the first optical element according to the light spot position image of the side-view imaging device collected by the global vision device, so that the first light spot and the second light spot tend to coincide.

[0049] The step of finely aligning the first optical element comprises: an optical absorption element is arranged between the second optical element and the planar mirror to cut off the light path between the second optical element and the planar mirror; the controller controls the second rotating platform to adjust the tilt angle of the first optical element; at the same time, the light intensity value of the reflected light beam of the planar mirror detected by the photodetector is monitored; when the light intensity value of the reflected light beam of the planar mirror detected by the photodetector is greater than a set threshold value, the second rotating platform is controlled to rotate to realize upward search scanning until the light intensity value of the reflected light beam of the planar mirror detected by the photodetector reaches a maximum value.

[0050] Preferably, the step of coarsely aligning the first optical element further comprises: the controller controls the first rotating platform to adjust the three-dimensional position of the first optical element according to the relative position between the first optical element and the second optical element collected by the first microscopic vision device and the second microscopic vision device, so that the first optical element and the second optical element are positionally aligned.

[0051] Preferably, the first optical element is a beam splitter prism, and the second optical element is a collimating lens; the side surface of the beam splitter prism is coated with a reflective film.

[0052] The application also provides a precise assembly method of a laser interferometer micro-probe sensor, which is applied to the precise assembly system of the laser interferometer micro-probe sensor and comprises the following steps:

[0053] The controller controls the first rotating platform and the second rotating platform through the visual feedback of the visual feedback device and the optical feedback of the photodetector, so as to realize the coarse alignment and fine alignment of the planar mirror in sequence, and then realize the coarse alignment and fine alignment of the first optical element in sequence.

[0054] After the alignment is completed, the dispensing device generates a precise amount of glue, and applies the glue between the second optical element and the first optical element by contact transfer;

[0055] After the dispensing is completed, the curing device irradiates from a direction perpendicular to the connection between the second optical element and the first optical element, thereby achieving the curing connection of the second optical element and the first optical element.

[0056] The present application has the following advantages:

[0057] 1. System architecture with high integration. Since the system covers key links such as alignment, dispensing, curing, etc. in the entire assembly process of the laser interferometer micro probe sensor, multiple mechanical structures in the system have high multiplexing, which greatly improves the integration of the entire system. For example, the upper surface of the clamp and the light emitting surface of the light source are used as an imaging screen at the same time to provide conditions for visual feedback. Such multiplexing mechanical structures simplify the system architecture, reduce the use of independent components, not only effectively reduce the complexity of the system, reduce the overall size, realize compact and efficient system integration, but also significantly improve the stability and reliability of the system.

[0058] 2. High-precision assembly process. Since visual feedback and optical feedback are used in the assembly process, combined with high-precision micro displacement tables as actuators, the attitude of the plane mirror and the beam splitter prism can be adjusted very subtly and accurately through the feedback signal. At the same time, the position and layout relationship between the various components also provides a strong guarantee for high assembly precision. For example, the clamp, the second holder, and the plane mirror are sequentially distributed along the vertical mounting axis from bottom to top, two microscopic vision devices are aligned with the assembly area from two orthogonal horizontal directions, the global vision device looks down on the assembly area from an oblique direction, and the curing device is arranged coplanarly around the assembly axis and the two microscopic vision devices, etc., so that the components can work closely and cooperate with each other, and the assembly error caused by the positional deviation between the components is minimized.

[0059] 3. Efficient assembly process, which can quickly and accurately complete the assembly of the laser interferometer micro probe sensor. During the alignment stage, the system first uses visual feedback to achieve coarse alignment, and the second holder and the plane reflector can be quickly adjusted to the approximately accurate position and attitude, greatly shortening the initial alignment time and laying a foundation for subsequent fine alignment. In addition, the entire assembly process is highly automated, and the assembly control subsystem collects information from the visual subsystem and the optical path subsystem in real time, and controls the motion of the actuators in each subsystem according to the information, greatly reducing the time loss caused by human intervention, avoiding errors caused by human factors, and greatly improving the assembly efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1A schematic diagram of the principle of the precision assembly system in the embodiment of the present application;

[0061] Figure 2 A three-dimensional schematic diagram of the precision assembly system of the micro-probe sensor in the embodiment of the present application;

[0062] Figure 3 A three-dimensional schematic diagram of the main part of the precision assembly system of the micro-probe sensor in the embodiment of the present application;

[0063] Figure 4 A top view of the main part of the precision assembly system of the micro-probe sensor in the embodiment of the present application;

[0064] Figure 5 A three-dimensional schematic diagram of the second rotating platform in the embodiment of the present application;

[0065] Figure 6 A three-dimensional schematic diagram of the second microscopic visualizer, micro-feeding device and first translation table in the embodiment of the present application;

[0066] Figure 7 A three-dimensional structural schematic diagram of the first gripper in the embodiment of the present application;

[0067] Figure 8 A three-dimensional schematic diagram of the main part of the precision assembly system of the micro-probe sensor in the embodiment of the present application;

[0068] Figure 9 A structural schematic diagram of the first gripper in the embodiment of the present application;

[0069] Figure 10 A schematic diagram of the principle of visual coarse alignment of the planar mirror in the embodiment of the present application;

[0070] Figure 11 A schematic diagram of the principle of visual coarse alignment of the light splitting prism in the embodiment of the present application;

[0071] Figure 12 A schematic diagram of the transmission of the reflected light beam in the collimating lens in the embodiment of the present application;

[0072] Figure 13 A three-dimensional schematic diagram of the principle of the spiral gradient ascent search in the embodiment of the present application;

[0073] Figure 14 A planar projection view of the principle of the spiral gradient ascent search in the embodiment of the present application;

[0074] Figure 15 A schematic diagram of the principle of clamping of the light splitting prism in the embodiment of the present application;

[0075] Figure 16Fig. 1 is a schematic diagram of a plane mirror in a non-rough alignment state collected by a global camera in a rough alignment process of a plane mirror in an embodiment of the present application;

[0076] Figure 17 Fig. 2 is a schematic diagram of a plane mirror in a rough alignment state collected by a global camera in a rough alignment process of a plane mirror in an embodiment of the present application;

[0077] Figure 18 Fig. 3 is a screen in a pre-positioning process of a beam splitter prism collected by a second microscopic vision device along an x-axis in an embodiment of the present application;

[0078] Figure 19 Fig. 4 is a screen in a pre-positioning process of a beam splitter prism collected by a first microscopic vision device along a y-axis in an embodiment of the present application;

[0079] Figure 20 Fig. 5 is a screen in a non-rough alignment state of a beam splitter prism collected by a global vision device in a rough alignment process of the beam splitter prism in an embodiment of the present application;

[0080] Figure 21 Fig. 6 is a screen in a rough alignment state of a beam splitter prism collected by a global vision device in a rough alignment process of the beam splitter prism in an embodiment of the present application;

[0081] Figure 22 Fig. 7 is a curve of a measured reflection light intensity normalized value changing with iteration number in a beam splitter prism alignment process in an embodiment of the present application;

[0082] Figure 23 Fig. 8 is a structural schematic diagram of a second holder in an embodiment of the present application;

[0083] 1 - plane mirror, 2 - solidifier, 3 - global vision device, 4 - second holder, 41 - clamp mechanism, 42 - force sensor, 43 - third base, 44 - electric heating sheet, 45 - magnetic connecting piece, 5 - first microscopic vision device, 6 - second microscopic vision device, 7 - clamp, 71 - imaging screen, 8 - micro-sampler, 9 - controller, 10 - laser, 11 - box, 12 - first rotating platform, 13 - second rotating platform, 14 - first flat light source, 15 - first holder, 16 - first translation stage, 17 - second translation stage, 18 - second flat light source, 19 - second rotating shaft fixing piece, 20 - second magnet slot, 21 - second base, 22 - second cover plate, 23 - first cover plate, 24 - first rotating shaft fixing piece, 25 - first magnet slot, 26 - first base, 27 - beam splitter prism, 28 - collimating lens, 29 - ring device, 30 - photodetector, 31 - side-view imaging device; 32 - axis. DETAILED DESCRIPTION

[0084] As Figure 1 , Figure 2 ,Figure 3 、 Figure 4 As shown in FIGS. 1-8, the application provides a precise assembly system for a laser interferometer micro-probe sensor, which comprises a box 11, a laser 10, a ring 29, a photoelectric detector 30 and a controller 9.

[0085] A plane mirror 1 is assembled on the tabletop of the box 11 through a first rotating platform 12;

[0086] A first optical element is assembled on the tabletop of the box 11 through a second rotating platform 13, which is arranged below the plane mirror 1;

[0087] A second optical element is assembled on the tabletop of the box 11 through a clamp 7, which is arranged below the first optical element, and the upper surface of the clamp 7 serves as an imaging screen 71 for the reflected light of the plane mirror 1;

[0088] A dispensing device is clamped by a first holder 15, which is assembled on the tabletop of the box 11 through a first translation table 16;

[0089] A curing device is assembled on the tabletop of the box 11 through a second translation table 17;

[0090] A side-view imaging device 31 is assembled on the tabletop of the box 11;

[0091] A visual feedback device is assembled on the tabletop of the box 11;

[0092] The output of the laser 10 is connected to the second optical element through the ring 29, the other output end of the ring 29 is connected to the photoelectric detector 30, and the output of the photoelectric detector 30 is connected to the controller 9;

[0093] The input of the controller 9 is connected to the visual feedback device, and the output is connected to the first rotating platform 12 and the second rotating platform 13;

[0094] The center of the plane mirror 1 coincides with the rotation center of the first rotating platform 12;

[0095] The center of the first optical element coincides with the rotation center of the second rotating platform 13;

[0096] The rotation center of the first rotating platform 12, the rotation center of the second rotating platform 13 and the central axis of the clamp 7 are arranged on the same axis 32;

[0097] The side-view imaging device 31 is arranged in parallel with the axis 32.

[0098] In the embodiment of the present application, with reference to Figure 2 , the box 11 is a closed cabinet structure, which can be divided into upper and lower parts. The upper half of the box is a closed structure with transparent glass around, which can isolate external influences and observe the assembly process in real time, and a display is installed in the right half area to provide a human-computer interaction interface; the top of the lower half of the box is placed with a precise assembly system mechanical structure of a laser interferometer micro probe sensor, and a partition is arranged inside for placing a laser 10, a ring-shaped device 29, a photoelectric detector 30 and a controller 9 of the precise assembly system of the laser interferometer micro probe sensor.

[0099] In the embodiment of the present application, the axis 32 is perpendicular to the table top of the box 11.

[0100] The output of the laser 10 is connected to the second optical element to be assembled through the ring-shaped device 29, the other output end of the ring-shaped device 29 is connected to the photoelectric detector 30, and the output of the photoelectric detector 30 is connected to the controller 9.

[0101] In combination with Figure 1 , the first rotating platform 12 is a two-axis rotating platform, which is a two-axis micro displacement table, including a first pitching turntable and a first yawing turntable, and the plane mirror 1 is assembled on the first rotating platform 12 through a mirror frame.

[0102] In combination with Figure 1 , the second rotating platform 13 includes a two-axis rotating platform and a three-axis translation table, and the two-axis rotating platform includes a second pitching turntable and a second yawing turntable arranged from top to bottom, the second optical element is assembled on the second pitching turntable through the second holder 4, and the second yawing turntable is assembled on the three-axis translation table (xyz-axis displacement table), so that the second rotating platform 13 serves as a five-axis micro displacement table.

[0103] In combination with Figure 1 , the first translation table 16 is a three-axis micro displacement table, specifically an x, y and z three-axis displacement table; and the second translation table 17 is a two-axis micro displacement table, specifically an x and z-axis displacement table, i.e. a lifting displacement table and a horizontal displacement table moving horizontally in the direction of the axis 32.

[0104] In the embodiment of the present application, the clamp 7 is printed with resin material D, with reference to Figure 9 , the clamp 7 includes a first cover plate 23, a first rotating shaft fixing member 24 and a first base 26.

[0105] The side surface of the first cover plate 23 is designed with a rotating shaft, which is matched with a hole in the side surface of the first base 26, and the two can rotate relative to each other to form a cylindrical structure after being folded. After the first rotating shaft fixing member 24 is inserted into the rotating shaft, the rotating shaft cannot be taken out.

[0106] The upper surfaces of the first cover plate 23 and the first base 26 are semicircular disc surfaces respectively; after the first cover plate 23 and the first base 26 are fixed by adsorption, the two semicircular disc surfaces form a complete circular disc surface, which will serve as an imaging screen 71 of reflected light of the plane mirror 1.

[0107] A semicircular groove is formed on the upper surface of the first cover plate 23 and the upper surface of the first base 26 along the respective axes downward respectively; after the first cover plate 23 and the first base 26 are fixed by adsorption, the two semicircular grooves together form a groove for clamping the second optical element.

[0108] A semicircular via hole is formed on the lower surface of the first cover plate 23 and the lower surface of the first base 26 along the respective axes upward respectively, and after the first cover plate 23 and the first base 26 are fixed by adsorption, the two semicircular via holes together form a fiber via hole for the optical fiber to pass through, and the optical fiber is connected to the second optical element assembled in the groove after passing through the fiber via hole from the bottom.

[0109] In the embodiment of the present application, the first cover plate 23 and the first base 26 are also adsorbed and attached by a magnetic adsorption part. Specifically, the first cover plate 23 and the first base 26 are respectively provided with opposite first magnet grooves 25, and magnets are installed in the first magnet grooves 25. The first cover plate 23 and the first base 26 are adsorbed and attached by the magnetic force of the magnets, so as to clamp the second optical element to be assembled.

[0110] In the embodiment of the present application, the magnets installed in the first cover plate 23 and the first base 26 are designed as four pairs, and the four pairs of magnets are uniformly distributed with respect to the axis of the clamp 7.

[0111] In combination with Figure 9 and Figure 10 , when working, the second optical element adsorbed and fixed by the magnets first falls into the semicircular groove on the first base 26 from above; then, the first cover plate 23 is manually rotated, and the first cover plate 23 and the first base 26 are folded and clamped to the second optical element under the magnetic adsorption of the magnets. The upper surfaces of the first cover plate 23 and the first base 26 after being folded together form a large disc-shaped target surface, which serves as the imaging screen 71 and is used to present the pointing direction of the reflected light beam of the plane mirror 1.

[0112] In combination with Figure 3 , Figure 4 and Figure 8 , in the embodiment of the present application, the visual feedback device comprises:

[0113] A first microscopic visualizer 5 is fixed on the tabletop of the box body 11 and arranged parallel to the side-view imaging device 31, and the field of view of the first microscopic visualizer 5 covers the butt joint area of the first optical element and the second optical element.

[0114] a second microscopic vision device 6 fixed on the table top of the box 11 and arranged perpendicularly to the side-view imaging device 31, a field of view of the second microscopic vision device 6 covering the abutting area of the first optical element and the second optical element;

[0115] a global vision device 3 fixed on the table top of the box 11, and an axis of the global vision device 3 pointing to the upper surface of the clamp 7 and the side-view imaging device 31;

[0116] An intersection of the axes between the first microscopic vision device 5 and the second microscopic vision device 6 is located on the axis 32.

[0117] For the first microscopic vision device 5 and the second microscopic vision device 6, the axes thereof are respectively arranged perpendicularly to the normal planes of the first optical element and the second optical element.

[0118] The first microscopic vision device 5 and the second microscopic vision device 6 respectively collect images of the abutting area of the first optical element and the second optical element from two directions, for the controller 9 to evaluate the position alignment between the first optical element and the second optical element.

[0119] The first microscopic vision device 5 and the second microscopic vision device 6 are respectively constituted by a camera head equipped with a microscopic lens, and the global vision device 3 is a global camera.

[0120] Referring to Figure 6 In an implementation manner, the second microscopic vision device 6 is fixed on the first translation stage 16, and the microscopic vision picture can be adjusted; the first holder 15 of the micro-injector 8 is placed obliquely, and does not interfere with the second microscopic vision device 6.

[0121] In another implementation manner, as shown in Figure 8 The rotating platform of the second microscopic vision device 6 can also be arranged not to be reused with the first translation stage 16 of the micro-injector 8. The micro-injector 8 is arranged on the right side of the second microscopic vision device 6, and a needle tube of the micro-injector 8 points to the axis 32.

[0122] Referring to Figure 3 and 5 In the embodiment, a first flat light source 14 is arranged on the side-view imaging device 31, and a center of the first flat light source 14 is located on an axis of the first microscopic vision device 5;

[0123] A second flat light source 18 is arranged on the second rotating platform 13, and a center of the second flat light source 18 is located on an axis of the second microscopic vision device 6;

[0124] The front surface of the first flat light source simultaneously serves as the imaging screen 71 of the side-view imaging device 31, and the first flat light source is parallel to the side surface of the first optical element coated with a reflective film.

[0125] With reference to Figure 6 In the embodiment of the present application, the dispensing device comprises a micro-syringe 8 fixed on the first translation stage 16 by a first holder 15;

[0126] The needle tube axis of the micro-syringe 8 is parallel to the exit end surface of the first optical element;

[0127] When dispensing, a precise amount of glue droplet is extruded by the micro-syringe 8, and the glue droplet is attached below the needle tip of the needle tube; the controller 9 controls the movement of the first translation stage 16 to move the needle tip of the micro-syringe 8 above the first optical element;

[0128] The controller 9 also extracts the height difference between the needle tip and the upper surface of the first optical element, the horizontal position difference between the needle tip and the upper surface of the first optical element, and the glue amount information of the glue droplet from the image obtained by the visual feedback device, so as to control the descent and translation of the first translation stage 16, so that the glue droplet is in contact with the center of the upper surface of the first optical element, and the contact transfer of the glue droplet is realized;

[0129] The controller 9 also extracts the glue amount attached to the end surface of the first optical element from the obtained image, so as to realize the precise control of the dispensing amount.

[0130] Wherein, the needle tip refers to the needle tip of the needle tube of the micro-syringe 8.

[0131] With reference to Figure 7 The first holder 15 comprises a second base 21, a second cover plate 22 and a second shaft fixing member 19;

[0132] The cover plate of the clamp 7 is rotatably connected to the table surface of the clamp 7 box body 11 through the shaft fixing member;

[0133] The second cover plate 22 and the second base 21 are provided with outwardly extending half hollow cylindrical structures, and the two half hollow cylindrical structures form a complete hollow cylindrical structure;

[0134] When in use, the needle tube of the micro-syringe 8 is fixed in the hollow groove of the hollow cylindrical structure;

[0135] The second cover plate 22 and the second base 21 are also attached by a second magnetic attraction member.

[0136] With reference to Figure 1 And Figure 3 In the embodiment of the present application, the curing device comprises a curing device 2 fixed on the second translation stage 17;

[0137] The end face of the curing device 2 is directed downward, the axis thereof is parallel to the mounting axis 32, and the movement direction of the lifting displacement table in the second translation table 17 is coplanar with the mounting axis 32;

[0138] During curing, the controller 9 controls the movement of the second translation table 17 to move the curing device 2 to a position directly above the connection between the second optical element and the first optical element, and then adjusts the height of the curing device 2 through the second translation table 17 to make the exit focal plane of the curing device 2 coincide with the connection between the second optical element and the first optical element.

[0139] In the embodiment of the application, the precise assembly system of the aforementioned laser interferometer micro-probe sensor is used to complete the following control process:

[0140] The controller 9 controls the first rotation platform 12 and the second rotation platform 13 through the visual feedback of the visual feedback device and the optical feedback of the photoelectric detector 30, so as to realize the rough alignment and the fine alignment of the plane mirror 1 in sequence, and then realize the rough alignment and the fine alignment of the first optical element in sequence.

[0141] After the alignment is completed, the dispensing device generates a precise amount of glue, and the glue is applied between the second optical element and the first optical element through contact transfer;

[0142] After the dispensing is completed, the curing device irradiates from a direction perpendicular to the connection between the second optical element and the first optical element, and realizes the curing connection of the second optical element and the first optical element.

[0143] The controller 9 controls the first rotation platform 12 and the second rotation platform 13 through the visual feedback of the visual feedback device and the optical feedback of the photoelectric detector 30, so as to realize the alignment of the position and the posture of the second optical element and the first optical element.

[0144] Specifically, in the embodiment of the application, the step of quickly aligning the optical element includes: sequentially performing rough alignment and fine alignment on the plane mirror 1, and then sequentially performing rough alignment and fine alignment on the first optical element.

[0145] The controller 9 controls the first rotation platform 12 and the second rotation platform 13 through the visual feedback of the visual feedback device and the optical feedback of the photoelectric detector 30, so as to realize the alignment of the position and the posture of the second optical element and the first optical element. Figure 10In the embodiment of the present application, the step of coarsely aligning the plane mirror 1 comprises: the controller 9 controls the second rotating platform 13 to move the first optical element away from the second optical element to the light beam path of the plane mirror 1, and then controls the laser 10 to emit light; the light emitted by the laser 10 is transmitted through the optical fiber, and then the emitted light is collimated through the second optical element and reflected by the plane mirror 1 to the imaging screen 71; and the controller 9 controls the first rotating platform 12 to adjust the posture of the plane mirror 1 according to the light spot position image of the imaging screen 71 collected by the global vision device 3, so that the reflected light beam of the plane mirror 1 is directed to the end face center of the imaging screen 71.

[0146] In the embodiment of the present application, the step of coarsely aligning the plane mirror 1 comprises: the controller 9 controls the second rotating platform 13 to move the first optical element away from the second optical element to the light beam path of the plane mirror 1, and then controls the laser 10 to emit light; the light emitted by the laser 10 is transmitted through the optical fiber, and then the emitted light is collimated through the second optical element and reflected by the plane mirror 1 to the imaging screen 71; and the controller 9 controls the first rotating platform 12 to adjust the posture of the plane mirror 1 according to the light spot position image of the imaging screen 71 collected by the global vision device 3, so that the reflected light beam of the plane mirror 1 is directed to the end face center of the imaging screen 71.

[0147] In the embodiment of the present application, the step of coarsely aligning the plane mirror 1 comprises: the controller 9 controls the second rotating platform 13 to move the first optical element away from the second optical element to the light beam path of the plane mirror 1, and then controls the laser 10 to emit light; the light emitted by the laser 10 is transmitted through the optical fiber, and then the emitted light is collimated through the second optical element and reflected by the plane mirror 1 to the imaging screen 71; and the controller 9 controls the first rotating platform 12 to adjust the posture of the plane mirror 1 according to the light spot position image of the imaging screen 71 collected by the global vision device 3, so that the reflected light beam of the plane mirror 1 is directed to the end face center of the imaging screen 71. Figure 11 In the embodiment of the present application, the step of coarsely aligning the plane mirror 1 comprises: the controller 9 controls the second rotating platform 13 to move the first optical element away from the second optical element to the light beam path of the plane mirror 1, and then controls the laser 10 to emit light; the light emitted by the laser 10 is transmitted through the optical fiber, and then the emitted light is collimated through the second optical element and reflected by the plane mirror 1 to the imaging screen 71; and the controller 9 controls the first rotating platform 12 to adjust the posture of the plane mirror 1 according to the light spot position image of the imaging screen 71 collected by the global vision device 3, so that the reflected light beam of the plane mirror 1 is directed to the end face center of the imaging screen 71.

[0148] The step of fine aligning the first optical element comprises: the controller 9 controls the second rotating platform 13 to rotate to realize spiral scanning, and adjusts the tilt angle of the first optical element; meanwhile, the light intensity value of the reflected light beam of the plane mirror 1 detected by the photodetector 30 is monitored, and when the light intensity value of the reflected light beam of the plane mirror 1 detected by the photodetector 30 is greater than a set threshold value, the second rotating platform 13 is controlled to rotate to realize upward search scanning until the light intensity value of the reflected light beam of the plane mirror 1 detected by the photodetector 30 reaches a maximum value.

[0149] The step of coarse aligning the first optical element further comprises: the controller 9 controls the second rotating platform 13 to adjust the position of the first optical element according to the relative position between the first optical element and the second optical element collected by the first microscopic vision device 5 and the second microscopic vision device 6, so that the first optical element and the second optical element are positionally aligned.

[0150] In the embodiments of the present application, the first optical element is taken as a beam splitter prism 27, and the second optical element is taken as a collimating lens 28 as an example, and the precise assembly system of the laser interferometer microprobe sensor in the embodiments of the present application is described in detail, wherein the side surface of the beam splitter prism 27 is coated with a reflective film.

[0151] The alignment principle of the beam splitter prism 27 and the collimating lens 28 is shown in Figure 10 and Figure 11 . It is assumed that the beam splitter prism 27 is an ideal cube, and the normal direction of the plane mirror 1 above the collimating lens 28 is parallel to the axial direction of the outgoing light beam, that is, the plane mirror 1 and the collimating lens 28 have been aligned. According to Figure 11 , in the aligned state, the outgoing light beam of the collimating lens 28 is divided into two paths by the beam splitter prism 27. One path is reflected by the half-reflecting and half-transmitting surface and the side surface coated with a film of the beam splitter prism 27 in turn, and then transmitted and reflected again by the half-reflecting and half-transmitting surface; the other path is reflected by the plane mirror 1 and then reflected and transmitted by the half-reflecting and half-transmitting surface. When the two light beams reach the end surface of the collimating lens 28 and the side-view imaging device 31, the axial lines coincide, and the light spots formed coincide. According to Figure 11 , when misaligned, two non-coincident light spots A and B are respectively generated on the side-view imaging device 31, and the coordinates of the two light spots A and B can be respectively expressed as:

[0152] A=(C1sinα(sinβ+cosαcosβ),C2(cosβ-sinαsinβ)) (1)

[0153]

[0154] wherein a is the roll angle of the light splitting prism 27, and β is the pitch angle of the light splitting prism 27. C1 and C2 are constants calibrated in advance, which depend on the size of the light splitting prism 27, the distance between the end face of the collimating lens 28 and the light splitting prism 27, and the distance l between the side-view imaging device 31 and the light splitting prism 27.

[0155] Since a and β are very small, sin a can be approximated as a, sin β can be approximated as β, and cos a and cos β can be approximated as 1. Further, based on the small angle approximation and by linear approximation through Taylor expansion, the distance between A and B can be expressed as:

[0156] d = k1a + k2β (3) wherein k1 and k2 represent the influence factors of a and β on the distance between A and B, respectively.

[0157] According to equation (3), the distance d between A and B is in a proportional relationship with the roll angle a and the pitch angle β of the light splitting prism 27. By observing and feedback controlling the distance d, the distance d can be made to approach 0, so as to achieve the coarse alignment between the light splitting prism 27 and the collimating lens 28.

[0158] It is considered that the outgoing light beam of the collimating lens 28 is an ideal Gaussian light beam, and the light beam characteristics do not change in the light beam transmission process. After the coarse alignment, the light beam reflected by the side surface coated reflecting surface of the light splitting prism 27 enters the collimating lens 28 at an angle γ after being reflected by the light splitting surface, and is coupled into the single-mode optical fiber, as shown in FIG. 3B. Figure 12 The coupling light field at the end face of the collimating lens 28 can be expressed as:

[0159]

[0160] wherein w0 is the beam waist radius of the outgoing laser of the laser 10, D γ is the offset between the incident light beam and the outgoing light beam of the collimating lens 28 due to the incident angle, which can be expressed as

[0161]

[0162] wherein n0 is the refractive index on the axis of the collimating lens 28, is the gradient constant.

[0163] According to equations (4) and (5), the coupling light field E(γ) at the end face of the collimating lens 28 is negatively related to the light beam incident angle γ. When γ is 0, the light splitting prism 27 is aligned with the collimating lens 28, and the coupling light field value at the end face of the collimating lens 28 is the maximum, which can be expressed as E0. The coupling efficiency η can be expressed as:

[0164]

[0165] Therefore, the light intensity of the light beam coupled into the collimating lens 28 can be expressed as:

[0166] I=I0η (7) Where I0 is the light intensity in the fully aligned state.

[0167] According to equation (7), when the intensity I of the light beam coupled into the collimating lens 28 is maximum, the coupling efficiency η is maximum, and the beam splitter prism 27 is aligned with the gradient index lens. The intensity I can be maximized by measuring the reflected light intensity I and using this as feedback to control the roll and pitch angles, achieving precise alignment between the beam splitter prism 27 and the collimating lens 28.

[0168] According to the above alignment principle, the alignment process of the beam splitter prism 27 and the collimating lens 28 is as follows: Figure 10 and Figure 11 As shown in FIG. The alignment process of the beam splitter prism 27 is divided into two stages: alignment of the plane reflector 1 and alignment of the beam splitter prism 27. Both the plane reflector 1 and the beam splitter prism 27 are aligned sequentially using a combination of visual feedback coarse alignment and optical feedback fine alignment to achieve rapid and accurate alignment. The first stage establishes a reference optical path, providing a reference light point B as an indicator for the second stage of visual feedback coarse alignment.

[0169] according to Figure 10 When the plane reflector 1 is roughly aligned, an imaging screen 71 with a circular hole in the center is fixed at the exit end face of the collimating lens 28, and a plane reflector 1 is placed above it. A 650nm wavelength red laser is used as the indicator light. The light emitted from the collimating lens 28 is reflected by the plane reflector 1 to form a light spot P on the imaging screen 71. The coordinates (x p ,y p ). According to the coordinates of the light point P in the plane coordinate system, the roll angle ψ and pitch angle θ of the plane reflector 1 can be expressed as

[0170]

[0171]

[0172] Where l is the distance from the exit end face of the collimating lens 28 to the plane reflector 1.

[0173] The tilt angle of the plane reflector 1 is adjusted according to the feedback of the solution result so that the reflected light beam points to the end face center of the collimating lens 28, thereby achieving rough alignment of the plane reflector 1 based on visual feedback.

[0174] When fine aligning the plane mirror 1, according to the detected light intensity I of the reflected light beam of the plane mirror 1, the search algorithm is used to calculate the adjustment amount, and the two tilt angles of the plane mirror 1 are adjusted so that I is maximum. At this time, the tilt angle γ between the reflected light beam and the collimating lens 28 is 0, and the fine alignment of the plane mirror 1 is realized.

[0175] In order to ensure faster search speed and obtain global optimal solution, the spiral gradient ascent search method is used in fine alignment, as shown in Figure 13 and Figure 14 The tilt angle during scanning can be expressed as

[0176]

[0177] where k is a parameter for controlling the pitch of the spiral line, which determines the amount of radius growth when the spiral line increases by a unit angle. ω is the angular velocity of the spiral scanning, and t is the time.

[0178] When the light intensity is greater than the set threshold, the scanning mode is switched to gradient ascent scanning. At this time, the tilt angle during scanning can be expressed as:

[0179]

[0180] where t represents the iteration number, η represents the gradient ascent learning rate, is the gradient ascent step size, is the light intensity gradient, which can be expressed as:

[0181]

[0182] where is the maximum value of the light intensity coordinate, and σ is a constant.

[0183] The position is updated along the gradient ascent direction, and the scanning is stopped when the gradient ascent step size is less than the preset step size. At this time, the end face incident light power of the collimating lens 28 reaches the maximum value, and the reference principal axis is established.

[0184] When the spectrometer prism 27 is roughly aligned, the distance d between the two light points A and B formed by the indicating light on the side-view imaging device 31 is measured as a loss function by the vision system, as shown in Figure 11The two tilt angles of the beam splitter prism 27 are adjusted iteratively based on the gradient descent algorithm to deflect the two beams simultaneously and to reduce d until the gradient descent distance is less than a preset minimum step size. At this time, the points A and B tend to coincide, d tends to 0, and the coarse alignment based on visual feedback is achieved. When the beam splitter prism 27 is precisely aligned, in order to avoid interference between the reflected beams of the plane mirror 1 and the upper surface coated reflecting surface of the beam splitter prism 27, the light power of the reflected beam is detected during alignment, and an optical absorption element is required during alignment to cut off the light path between the collimating lens 28 and the plane mirror 1. Similarly, the reflected light intensity received by the optical fiber is read, the beam splitter prism 27 is deflected using the spiral gradient ascent search algorithm, and the posture with the maximum reflected light intensity is found. According to equation (7), the deflection angle between the beam splitter prism 27 and the collimating lens 28 is close to 0 at this time, and precise alignment is achieved.

[0185] In the embodiment of the present application, the clamping principle of the beam splitter prism 27 is as shown in Figure 15 In order to ensure that the light paths in three orthogonal directions are not affected and to facilitate visual feedback and optical feedback during alignment, the second clamp 4 clamps the beam splitter prism 27 at an angle of 45°. The clamping mechanism 41 of the second clamp 4 includes two elastic plates made of bimetallic materials, and an electric heating sheet 44 is attached to the end of the elastic plate. The end of the second clamp 4 is integrated with a force sensor 42, which can measure the assembly force when the beam splitter prism 27 is in contact with the collimating lens 28, facilitating force feedback control. In addition, the clamping mechanism 41 and the third base 43 are connected by magnetic adsorption, facilitating the separation of the clamping mechanism 41 to clamp the beam splitter prism 27 to be assembled.

[0186] When clamping, the clamping force F is generated by the elastic deformation of part of the elastic plate of the clamping mechanism 41, which can be represented as:

[0187]

[0188] where E is the equivalent elastic modulus of the elastic plate, w is the width of the elastic plate, h is the thickness of the elastic plate, l is the length from the front end of the clamping jaw to the fixed position, i.e. the effective length, and δ is the difference between the size of the object and the distance between the clamping jaw, i.e. the deflection of the clamping jaw caused by the object.

[0189] When released, the electric heating sheet heats the bimetallic sheet, causing the bimetallic sheet to bend, the distance to increase, and the clamping jaw to open. When the displacement Δd of the front end of the clamping jaw is greater than δ, the clamping force of the clamp on the beam splitter prism 27 is 0, and precise release during assembly is achieved. Δd can be represented as

[0190]

[0191] where k is the geometric magnification factor of the cross clamping jaw, which is determined by the angle of the clamping jaw and the lever structure, and α Aand a B respectively, are the thermal expansion coefficients of different layers of the bimetallic sheet.

[0192] Referring to Figure 23 In the embodiment of the present application, the second holder 4 specifically comprises: a clamp mechanism 41, a force sensor 42, a third base 43, an electric heating sheet 44, and a magnetic connecting piece 45; the third base 43 is assembled on the second rotating platform 13 and follows the second rotating platform 13 to change the position in multiple dimensions; one end of the force sensor 42 is detachably connected with the second rotating platform 13, and the other end is detachably connected with the magnetic connecting piece 45; the clamp mechanism 41 is magnetically adsorbed on the magnetic connecting piece 45 after clamping the beam splitter prism 27; the electric heating sheet 44 is assembled on the clamp mechanism 41; the clamp mechanism 41 is magnetically adsorbed on the magnetic connecting piece 45 after clamping the beam splitter prism 27; the electric heating sheet 44 is assembled on the clamp mechanism 41; the magnetic connecting piece 45 with different thicknesses is replaced according to the thickness of the beam splitter prism 27, so as to ensure that the geometric center of the beam splitter prism 27 clamped by the clamp mechanism 41 is always located at the rotation center position of the second rotating platform 13; the clamp mechanism 41 releases the beam splitter prism 27 under the action of the electric heating sheet 44 after the beam splitter prism 27 is fixed with the collimating lens 28; the sensitive axis of the force sensor 42 is parallel to the assembly axis 32 of the beam splitter prism 27 and the collimating lens 28, so as to measure the assembly force generated when the beam splitter prism 27 is assembled on the collimating lens 28.

[0193] The clamp mechanism 41 of the second holder 4 comprises two elastic plates made of bimetallic materials respectively. The bimetallic material is a composite material made of two metals (or alloys) with different thermal expansion coefficients. Due to the difference in thermal expansion coefficients of the two metals, they will expand or shrink at different rates when the temperature changes, thereby producing bending or deformation.

[0194] When the electric heating sheet 44 is installed on the inner walls of the first elastic plate and the second elastic plate made of bimetallic materials and is powered to heat, the heat generated by the electric heating sheet 44 will cause the temperature of the bimetallic material to rise; uneven expansion causes the bimetallic material plate to bend and deform when heated. Specifically, if the metal layer with a smaller thermal expansion coefficient is located on the inner side (i.e., the side close to the electric heating sheet 44), then as the temperature rises, the expansion of the metal layer on the outer side will be more significant than that of the metal layer on the inner side, thereby causing the first elastic plate and the second elastic plate to bend inward, i.e., the first elastic plate and the second elastic plate open, achieving the release of the beam splitter prism 27.

[0195] In the embodiment of the present application, the laser 10 generates laser light which enters the first port of the circulator 29, exits from the second port of the circulator 29 and enters the optical fiber, and the reflected light beam exits from the third port of the circulator 29 and enters the photodetector 30. The photosensitive surface of the photodetector 30 has a diameter of 1 mm, for example, and a working wavelength of 800-1700 nm, a peak response wavelength of 1550 nm, and a responsivity of 0.9 mA / mW. The planar mirror 1 is installed at the center of the first rotating platform 12. The planar mirror 1 has a reflection efficiency of 95% for a 1550 nm wavelength laser, effectively reducing the transmission loss of the light beam.

[0196] To verify the effectiveness of the precise assembly device of the micro-probe sensor provided in the embodiment of the present application, experiments are performed.

[0197] In the coarse alignment of the planar mirror 1, the picture acquired by the global vision device is as shown in Figure 16 and Figure 17 According to Figure 16 , before alignment, the light spot of the reflected light beam of the planar mirror 1 on the target surface on the upper surface of the clamp 7 is located at the upper right of the center point in the figure. In LabVIEW, the target surface area is extracted from the picture and corrected by a vision measurement algorithm, the coordinates of the light spot in the target surface coordinate system are obtained, and the adjustment amount of the roll angle and the pitch angle of the planar mirror 1 is solved according to equations (8) and (9). The first rotating platform is driven to produce deflection, so that the reflected light beam is directed to the center position of the target surface, and the coarse alignment of the planar mirror 1 is realized, as shown in Figure 17 .

[0198] In the pre-positioning of the light-splitting prism 27, the pictures acquired by the first microscopic vision device 5 and the second microscopic vision device 6 are as shown in Figure 18 and Figure 19 . Figure 18 and Figure 19 are respectively pictures from the direction perpendicular to the light-splitting surface of the light-splitting prism 27 and the direction facing the light-splitting surface. By using a vision algorithm, the relative pose data between the light-splitting prism 27 and the collimating lens 28 are obtained by edge extraction and image measurement on the profile of the light-splitting prism 27 and the collimating lens 28. According to the data, the pose of the light-splitting prism 27 is adjusted by driving the micro-displacement stage, so that the lower surface of the light-splitting prism 27 is parallel to the upper surface of the collimating lens 28, and the median surface of the light-splitting prism 27 in the vertical direction passes through the axis of the collimating lens 28, thereby realizing the pre-positioning of the light-splitting prism 27.

[0199] In the coarse alignment of the light-splitting prism 27, the picture acquired by the global vision device is as shown in Figure 20 and Figure 21 According to Figure 20At this time, two non-coincident red light spots A and B appear in the side-view imaging device 31, the distance between the two points A and B is measured by visual measurement, and the roll angle and pitch angle of the light splitting prism 27 are adjusted accordingly to make the two points A and B coincide, and the coarse alignment of the light splitting prism 27 is completed, as shown in Figure 21

[0200] In the fine alignment process of the light splitting prism 27, the normalized value of the reflected light intensity changes with the number of iterations, as shown in the figure. According to Figure 22 In the alignment process, the threshold value of the spiral gradient ascent search is set to 0.15 times the maximum light intensity. After 43 iterations of spiral search, the measured light intensity exceeds the threshold value, and the gradient ascent search mode is switched, and after 8 iterations, the maximum light intensity point is found, and the fine alignment of the light splitting prism 27 is realized, and the alignment angle accuracy is ±0.01°.

[0201] In the dispensing and curing process, 1.6 μL of glue droplet is extruded through the micro-syringe 8, the micro-displacement table is controlled to rise and fall, the glue droplet is in contact with the upper surface of the gradient refractive index lens, and the glue droplet is attached to the end face of the gradient refractive index lens. The volume of the transferred glue droplet can be obtained by measuring the size and contact angle of the glue droplet in the image. By controlling the movement of the light splitting prism 27, it is in contact with the glue, and fills the gap between the light splitting prism 27 and the gradient refractive index lens, while monitoring the change of light intensity and adjusting the attitude. Under the premise of minimum light intensity loss, the light splitting prism 27 is moved downward, and the force sensing result of the clamping module is monitored to ensure that the assembly force is within a certain range, and the light splitting prism 27 and the gradient refractive index lens surface are attached.

[0202] The experimental results show that the assembly method established in the application embodiment can realize the rapid and automatic alignment of the light splitting prism 27 and the collimating lens 28 in the laser interferometer micro-sensing probe, accurate dispensing and curing, and the whole assembly process is completed within 2 minutes, the alignment angle accuracy is ±0.01°, which can meet the needs of precise assembly of the laser interferometer micro-sensing probe.

[0203] In the above specification, the main content of the application has been described by examples. However, various modifications and changes can be made without departing from the main content of the application as set forth in the claims. The drawings in the specification are illustrative rather than limiting. Therefore, the scope of the application should be determined by the claims and the equivalent forms or entities specified by the compound law, rather than only by the described examples.​

Claims

1. A precise assembly system for a laser interferometer microprobe sensor, characterized in that: include: Box, laser, circulator, photodetector and controller; A plane reflecting mirror is mounted on the table of the box through a first rotating platform; a first optical element, which is mounted on the table of the box through a second rotating platform, and the first optical element is arranged below the plane reflector; a second optical element, which is mounted on the table of the box by a fixture, the second optical element is arranged below the first optical element, and the upper surface of the fixture serves as an imaging screen for the reflected light of the plane reflector; A dispensing device, which is clamped by a first clamper, and the first clamper is assembled on the table of the box through a first translation stage; A curing device, which is assembled on the table of the box through a second translation table; A side-view imaging device, mounted on the table of the box; a visual feedback device mounted on the table of the box; The output of the laser is connected to the second optical element through a circulator, the other output end of the circulator is connected to the photodetector, and the output of the photodetector is connected to the controller; The input of the controller is connected to the visual feedback device, and the output is connected to the first rotating platform, the second rotating platform, the first translation platform and the second translation platform; The center of the plane reflector coincides with the rotation center of the first rotating platform; The center of the first optical element coincides with the rotation center of the second rotating platform; The rotation center of the first rotating platform, the rotation center of the second rotating platform and the central axis of the clamp are arranged on the same axis; The side-view imaging device is arranged parallel to the axis.

2. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The controller controls the first rotating platform and the second rotating platform through the visual feedback of the visual feedback device and the optical feedback of the photodetector to achieve alignment of the position and posture of the second optical element with the first optical element; After the position and posture of the second optical element and the first optical element are aligned, the dispensing device produces a precisely measured amount of glue and applies the glue between the second optical element and the first optical element by contact transfer; After the dispensing is completed, the curing device is used to irradiate downward from a position perpendicular to the connection between the second optical element and the first optical element, thereby achieving a cured connection between the second optical element and the first optical element.

3. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The dispensing device includes a micro-injector, which is fixed on the first translation stage through a first clamp; The needle axis of the microinjector is parallel to the emission end face of the first optical element; During dispensing, a precisely quantified amount of glue droplets is squeezed out through a micro-injector, and the glue droplets adhere to the bottom of the needle tip of the needle tube; the controller controls the movement of the first translation stage to move the needle tip of the micro-injector to the top of the first optical element; The controller also extracts information about the height difference between the needle tip and the upper surface of the first optical element, the horizontal position difference between the needle tip and the upper surface of the first optical element, and the amount of glue in the glue droplet based on the image acquired by the visual feedback device, so as to control the first translation stage to descend and translate so that the glue droplet contacts the center of the upper surface of the first optical element, thereby achieving contact transfer of the glue droplet. The controller also extracts the amount of glue attached to the end face of the first optical element based on the obtained image, thereby achieving precise control of the glue dispensing amount.

4. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The curing device includes a curing device, which is fixed on the second translation stage; The light-emitting end face of the curing device is directed downward, and its axis is parallel to the axis, and the movement direction of the lifting platform in the second translation stage is coplanar with the axis; During curing, the controller controls the movement of the second translation stage to move the curing device to the top of the connection between the second optical element and the first optical element, and then adjusts the height of the curing device through the second translation stage so that the exit focal plane of the curing device coincides with the connection between the second optical element and the first optical element.

5. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The output laser of the laser includes the laser of the working wavelength and the visible indicator laser, and the central wavelength of the photodetector is the working wavelength; When the visual feedback is aligned, the visible indicator laser provides an indicator light spot; when the optical feedback is aligned, the photodetector detects the laser light intensity of the working wavelength and transmits it to the controller as a light intensity feedback signal.

6. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The clamp comprises: a first base, a first cover plate and a first rotating shaft fixing member; The first cover plate is rotatably connected to the first base via the first rotating shaft fixing member; The upper surface of the first cover plate and the first base together serve as an imaging screen for the reflected light of the plane reflector; A groove for fixing the second optical element is formed on the axis of the first cover plate and the first base; An optical fiber passing groove is formed on the axis of the first cover plate and the first base, and the optical fiber passing groove is connected to the groove; The first cover plate and the first base are also adsorbed and attached to each other through a first magnetic adsorption component; The first clamper includes: a second base, a second cover plate and a second shaft fixing member; The fixture cover is rotatably connected to the table of the fixture box through the rotating shaft fixing member; The second cover plate and the second base are provided with a semi-hollow cylindrical structure extending outward, and the two semi-hollow cylindrical structures form a complete hollow cylindrical structure; When in use, the needle tube of the microinjector is fixed in the hollow groove of the hollow circle structure; The second cover plate and the second base are also adsorbed and attached via a second magnetic adsorption component.

7. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The alignment process of the plane reflector includes coarse alignment and fine alignment; The alignment process of the first optical element includes coarse alignment and fine alignment; The step of coarsely aligning the plane reflector includes: the controller controls the second rotating platform to move the first optical element away from the second optical element to the beam path of the plane reflector, and then controls the laser to emit light outward; the light emitted by the laser is transmitted through the optical fiber, the outgoing light is collimated by the second optical element, and then reflected by the plane reflector onto the imaging screen; the controller controls the first rotating platform to adjust the posture of the plane reflector based on the light spot position image on the imaging screen collected by the global vision device, so that the reflected light beam of the plane reflector points to the center of the end face of the imaging screen; The step of finely aligning the plane reflector includes: firstly, the controller controls the first rotating platform to rotate to perform spiral scanning and adjust the tilt angle of the plane reflector; at the same time, monitoring the intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector; when the intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector is greater than a set threshold, firstly controlling the first rotating platform to rotate to perform ascending search scanning until the intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector reaches a maximum value; The steps of coarsely aligning the first optical element include: the controller controls the second rotating platform to move the first optical element into the beam path from the second optical element to the plane reflector, and then controls the laser to emit light outward; the light emitted by the laser is transmitted through the optical fiber, and the outgoing light is collimated by the second optical element, and the collimated outgoing light is separated into reference light and measurement light by the first optical element, the reference light is reflected by the plane reflector to form a first light spot on the side-view imaging device, and the measurement light is emitted to form a second light spot on the side-view imaging device; the controller controls the second rotating platform to adjust the posture of the first optical element according to the light spot position image on the side-view imaging device captured by the global vision device, so that the first light spot and the second light spot tend to overlap; The steps of finely aligning the first optical element include: setting a light absorbing element between the second optical element and the plane reflector to cut off the light path between the second optical element and the plane reflector; the controller controls the second rotating platform to adjust the inclination angle of the first optical element; at the same time, monitoring the light intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector, and when the light intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector is greater than a set threshold, first controlling the second rotating platform to rotate to realize an ascending search scan until the light intensity value of the reflected light beam of the plane reflector detected by the photoelectric detector reaches a maximum value.

8. The precise assembly system of the laser interferometer microprobe sensor according to claim 7, characterized in that: The step of coarsely aligning the first optical element also includes: the controller also controls the first rotating platform to perform three-dimensional position adjustment on the first optical element based on the relative position between the first optical element and the second optical element captured by the first microscopic visual device and the second microscopic visual device, so as to align the first optical element and the second optical element.

9. The precise assembly system of the laser interferometer microprobe sensor according to claim 1, characterized in that: The first optical element is a beam splitter prism, and the second optical element is a collimating lens; the side surface of the beam splitter prism is coated with a reflective film.

10. A method for accurately assembling a laser interferometer microprobe sensor, applied to the accurate assembly system for a laser interferometer microprobe sensor according to any one of claims 1 to 9, characterized in that: The method comprises: The controller controls the first rotating platform and the second rotating platform through visual feedback from the visual feedback device and optical feedback from the photodetector, so as to sequentially perform coarse alignment and fine alignment on the plane reflector, and then sequentially perform coarse alignment and fine alignment on the first optical element; After the alignment is completed, the dispensing device produces a precisely measured amount of glue and applies the glue between the second optical element and the first optical element by contact transfer; After the dispensing is completed, the curing device is used to irradiate downward from a position perpendicular to the connection between the second optical element and the first optical element, thereby achieving a cured connection between the second optical element and the first optical element.

Images