Method and device for adjusting and measuring detector of pulse laser receiving system

Abstract

The invention discloses a method for bonding, adjusting and positioning a laser receiver detector, which comprises the following steps of: S1, mounting and adjusting a device for bonding, adjusting and positioning the laser receiver detector, S2, emitting a light beam vertical to an incident surface of a reflector sub-component by a laser; s3, acquiring data according to an image detection part in the photoelectric autocollimator, determining a deviation angle alpha of the clamp adapter plate, and adjusting a test board of the four-degree-of-freedom automatic adjustment tool by using an electric rotating table; and S4, the four-degree-of-freedom automatic adjusting tool is controlled by the motion control card for adjustment, a voltage data set is obtained by the oscilloscope, the maximum corresponding voltage positions of the detector in the X direction, the Y direction and the Z direction are determined, and the coordinate positions of the three systems are the optimal installation positions of the detector. The optimal assembly position of the detector can be accurately positioned, and the optimal performance and reliability of the laser receiver are ensured.

Description

Technical Field

[0001] The present invention relates to the field of optical system assembly and adjustment, and is mainly used for optimizing and adjusting the assembly position of a detector in a pulse laser receiving system. The device can realize automatic positioning of the detector at the optimal assembly position, ensuring the best working performance of the receiver. Background Art

[0002] The pulse laser receiving system is a device based on optical sensing technology, mainly composed of a receiving optical system, a photodetector and an amplifier. It is widely used in the fields of laser ranging, target positioning and precision measurement. The laser receiving optical system is a non-sequential optical detection system. The production process of the pulse laser receiving system mainly includes the bonding of the reflective prism and the assembly of the photodetector. First, after the reflective prism is bonded, the reflective mirror components are formed, and then the detector is assembled on its basis. Figure 4 After the light source enters the reflective prism, it undergoes internal reflection and is ultimately guided to the photosensitive area of ​​the photodetector. The assembly position of the photodetector and reflective prism directly affects the amount of incident light in the photosensitive area, which in turn affects the performance of the pulsed laser receiving system. The accuracy of the assembly and adjustment of the optical internal reflection prism and the photodetector determines the detection angle and detection capability distribution of the optical detection receiving system. If the detector bonding and assembly are not in the optimal position, the following problems will occur:

[0003] 1. Decreased receiving efficiency: The deviation of the photodetector position will cause the received beam to shift, thereby reducing the receiving efficiency of the laser signal and directly affecting the receiver performance.

[0004] 2. Optical path mismatch: Improper placement of the photodetector may disrupt the overall alignment of the optical system, resulting in uneven distribution of received signal intensity, which in turn affects the system's response speed and measurement accuracy.

[0005] 3. Unstable performance: The randomness of the photoelectric detector's assembly and adjustment may make it difficult to ensure assembly quality, affecting the reliability of the receiver.

[0006] Currently, photoelectric detector assembly and adjustment methods often rely on manual adjustments or empirical judgment, lacking precise assembly guidance and automated means. This results in low assembly accuracy and poor consistency. Multiple trial assembly and repeated testing lead to low assembly efficiency and low mass production efficiency. Therefore, there is an urgent need to develop an adjustment method and device that can automatically locate the optimal assembly position of photoelectric detectors in laser receivers to ensure the detectors are in the optimal assembly state and improve the performance and reliability of the receivers. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method and device for adjusting the optimal assembly position of a detector of a pulsed laser receiving system. By adopting the device and method, the optimal assembly position of the detector can be quickly adjusted and accurately positioned, thereby ensuring the optimal working performance of the pulsed laser receiving system.

[0008] To achieve the above object, the technical solution of the present invention is:

[0009] A method for debugging a detector of a pulsed laser receiving system comprises the following steps:

[0010] S1. Installation and debugging of a device for bonding, assembling and positioning of a laser receiver detector, comprising a computer and an electrically controlled rotary table, wherein the electrically controlled rotary table is mounted on a horizontal optical platform and electrically connected to a motion controller, a four-degree-of-freedom automatic adjustment tool is fixed to the electrically controlled rotary table by limit screws and electrically connected to a motion control card, the four-degree-of-freedom automatic adjustment tool comprises a test bench and a detector fixture, the test bench comprises a Z-axis electric translation table, a Y-axis electric translation table, an X-axis manual translation table, an XY plane electric rotation table and a fixture adapter plate, a reflector subassembly is placed on the fixture adapter plate, the reflector subassembly is placed on the test bench, the detector is clamped by the detector fixture and electrically connected to an oscilloscope to obtain a response voltage, a photoelectric autocollimator is fixed directly above the incident surface of the reflector subassembly by a lifting column, an image detection component is provided in the photoelectric autocollimator, the image detection component is connected to the computer, the laser is connected to the autocollimation light tube of the photoelectric autocollimator by magnetic attraction and emits a light beam directed to the reflector subassembly, and the laser emitted light beam is perpendicular to the incident surface of the reflector subassembly;

[0011] S2. The laser emits a beam perpendicular to the incident surface of the reflector subassembly;

[0012] S3. Determine the deviation angle α of the fixture adapter plate based on the data collected by the internal image detection component of the photoelectric autocollimator, and adjust the fixture adapter plate of the four-degree-of-freedom automatic adjustment tool using an electric rotary stage;

[0013] S4. Use the motion control card to control the four-degree-of-freedom automatic adjustment fixture for adjustment. Use the oscilloscope to obtain the voltage data set and determine the maximum corresponding voltage position of the detector in the X, Y, and Z directions. This three-axis coordinate position is the optimal installation position for the detector.

[0014] In step S3, the deflection angle α is:

[0015]

[0016] Where f represents the focal length of the objective lens of the photoelectric autocollimator; n is the pixel coordinate difference between the center of the cross spot after reflection and the center of the beam axis; α is the pixel size.

[0017] An infrared display card is attached to the incident surface of the reflector component for observing the light spot.

[0018] The optical platform is made of ferromagnetic stainless steel with a flatness not greater than 0.1.

[0019] The four-degree-of-freedom automatic adjustment fixture can adjust the displacement in the three directions of XYZ and the rotation in the XY plane.

[0020] Step S4 includes:

[0021] S41. Move the detector in the X-axis direction to the initial adjustment position, so that the center of the detector is equidistant from the two edges of the reflector subassembly extending in the Y-direction. Move the detector using the XY-plane motorized rotary stage until the two edges of the detector extending in the Y-direction are aligned with the two edges of the receiver's reflector subassembly extending in the Y-direction. Secure the detector fixture in the X-axis position.

[0022] S42. Control the Z-axis motorized translation stage to raise the detector by 0.7 mm. Then, control the Y-axis motorized translation stage to move the detector within the Y-axis travel range. During this movement, the detector response voltage output is collected using an oscilloscope according to the set step size to obtain a response voltage data set. This data set is analyzed to record the maximum response voltage and the current Z-axis position coordinates.

[0023] S43. Control the Z-axis motorized translation stage to raise the detector by 0.1 mm. As in step 6, control the Y-axis motorized translation stage to move again, traversing the Y-axis travel range to find the maximum response voltage. Record this maximum value and the current Z-axis position. Repeat this process until the maximum response voltage is found when the Z-axis coordinate is raised by 1.5 mm.

[0024] S44. Based on the data sets of multiple sets of Z-axis coordinates and maximum response voltages in the range of 0.7 mm to 1.5 mm obtained in S42 and S43, the Z-axis coordinate at which the maximum response voltage is located is located. Based on the data set, the Z-axis electric translation stage is controlled to move to the Z-axis coordinate corresponding to the maximum response voltage.

[0025] S45. Repeat the operation in step S42 at this position to find the Y-axis coordinate corresponding to the maximum value of the response voltage, and finally determine this position as the optimal assembly position of the detector.

[0026] This paper proposes a four-degree-of-freedom detector assembly and adjustment device based on multi-point detection and automatic positioning. Equipped with a four-degree-of-freedom detector adjustment tool, this device enables precise movement of the detector in four directions. Using an oscilloscope, the device captures the response voltage in real time. Based on the changing trend of the voltage signal, the optimal detector assembly position is precisely determined, ensuring optimal performance and reliability of the pulsed laser receiving system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the device of the present invention;

[0028] Figure 2 Automatic adjustment of the three-dimensional structure diagram of the tooling with four degrees of freedom;

[0029] Figure 3 Photoelectric autocollimator measurement principle diagram;

[0030] Figure 4 Schematic diagram of the assembly of photoelectric detector and reflector components. DETAILED DESCRIPTION

[0031] like Figure 1-3As shown, a device for bonding, assembling and positioning a pulse laser receiver detector includes an optical platform 1, an electric rotating platform 2, a four-degree-of-freedom automatic adjustment tool 3, a motion controller 4, a four-degree-of-freedom automatic adjustment tool motion control card 5, an oscilloscope 6, a photoelectric detector 7, a reflector sub-assembly 8, a photoelectric autocollimator 9, a computer 11, and a laser 12; the optical platform 1 uses a ferromagnetic stainless steel table with a flatness of ≤0.1 and a table size of 1500×1000×50mm (length×width×thickness); the electric rotating platform 2 includes two electric rotating platforms, each of which is divided into The two electric rotary tables are controlled by an electric rotary motor, respectively, so that the tabletops of the two electric rotary tables can rotate around two mutually orthogonal horizontal axes. The electric rotary motor of the second electric rotary table is fixed to the surface of the first electric rotary table, and the electric rotary motor of the first electric rotary table is fixed to the surface of the optical platform 1. The optical platform 1 and the first electric rotary table, as well as the first and second electric rotary tables, are separated from each other. The electric rotary motors are both stepper rotary tables with a tabletop diameter of 100mm, a transmission ratio of 180:1, a rotation angle of 360°, a resolution of 0.00125°, and a positioning repeatability of ≤0.004°, the output shafts of the two electric rotating motors are orthogonal to each other and parallel to the surface of the first electric rotating table of the electric rotating table 2; the four-degree-of-freedom automatic adjustment fixture 3 includes a test bench and a detector fixture 18, the detector fixture is installed on the test bench, wherein the test bench is composed of a Z-axis electric translation table 13, a Y-axis electric translation table 14, an X-axis manual translation table 15, an XY plane electric rotating table 16 and a fixture adapter plate 17, the receiver's reflector subassembly 8 is placed on the fixture adapter plate, the detector fixture is used to clamp the photodetector 7, the test bench is used to realize the movement of the detector fixture on the X-axis, Y-axis, and Z-axis, and rotation around the Z-axis, that is, four-axis displacement. As an optional implementation scheme, the Z-axis electric translation table 13 is fixed on the upper side of the Y-axis electric translation table 14, The Y-axis electric translation stage 14 is used to drive the Z-axis electric translation stage 13 to move in the Y direction. A detector fixture 18 is installed on one side of the Z-axis electric translation stage 13. The detector fixture 18 includes a clamping mechanism, a sliding table, and a sliding table. The clamping mechanism is connected to the Z-axis electric translation stage 13 along a guide shaft arranged in the X direction. The clamping mechanism can move in the Z-axis direction with the Z-axis electric translation stage 13 and can move in the X-axis direction relative to the Z-axis electric translation stage 13. The clamping mechanism is slidably connected to the sliding table through guide rails and slide grooves. The clamping mechanism can move in the Y direction relative to the sliding table, that is, the Z-axis electric translation stage 13 is allowed to drive the detector fixture 18 to move in the Z direction and the clamping mechanism is allowed to move in the Y direction with the Z-axis electric translation stage 13. The sliding table is connected to the X-axis manual translation stage 15. The XY plane electric rotation table 16 on the side is connected, that is, the clamping mechanism and the sliding table are allowed to move with the X-axis manual translation stage 15 in the X-axis direction relative to the Z-axis electric translation stage 13. The guide rails and slide grooves of the sliding table and the clamping mechanism are matched with each other, and the guide shaft of the Z-axis electric translation stage 13 is matched with the clamping mechanism, allowing the clamping mechanism to slightly adjust the angle around the Z axis under the operation of the XY plane electric rotation table 16. Among them, electric translation slides are used in the Y and Z axis directions, with a table diameter of 40mm, a moving stroke of 15mm, a resolution of 2μm, and a repeatability accuracy of 1μm; the XY direction electric rotation table uses an electric rotation table to realize rotation around the Z axis, with a table diameter of 60mm, a transmission ratio of 90:1, a rotation angle of 360°, a resolution of 0.00125°, and a positioning accuracy of 1μm. Repeatability ≤ 0.01°; the X-axis translation stage utilizes a manual slide with a table diameter of 34mm, a displacement range of 13mm, and a resolution of 0.002mm; the motion controller 4 is compatible with the motor used in the electric rotary stage 2 and the XY electric rotary stage in the four-degree-of-freedom automatic adjustment fixture 3; the motion control card 5 utilizes a positive motion control board, working in conjunction with a servo driver to drive the electric translation stages (Z-axis electric translation stage 13 and Y-axis electric translation stage 14); the oscilloscope 6 is a digital oscilloscope with four analog channels, a 100MHz analog channel bandwidth, and an acquisition rate of 2.5GS / s; the computer 11 is an industrial control computer; and the laser light source 12 is a modulated light source with a wavelength of 905nm, adjustable in frequency, pulse width, and peak power.

[0032] The first electric rotary stage of the electric rotary stage 2 is installed on the platform of the optical platform 1 and is electrically connected to the motion controller 4. The motion controller 4 controls the first electric rotary stage of the electric rotary stage 2 to rotate in the XZ plane (that is, the electric rotary stage 2 rotates around the Y axis), and controls the second electric rotary stage of the electric rotary stage 2 to rotate in the YZ plane (that is, the electric rotary stage 2 rotates around the X axis), adjusts the deviation angle between the normal of the second electric rotary stage of the electric rotary stage 2 and the optical axis of the light source, and the four-degree-of-freedom automatic adjustment fixture 3 is connected to the screw hole on the uppermost second electric rotary stage of the electric rotary stage 2 through the limit screw on the fixture adapter plate The two are fixedly connected as one. The four-degree-of-freedom automatic adjustment tool 3 includes a test bench and a detector fixture. The fixture adapter plate of the test bench is used to place the reflector sub-component 8, and the detector fixture is responsible for clamping the detector 7. The four-degree-of-freedom automatic adjustment tool 3 is used to realize the precise displacement of the detector fixture relative to the reflector sub-component 8 in the X, Y, and Z directions. The four-degree-of-freedom automatic adjustment tool 3 is electrically connected to the motion control card 5 and is controlled by it. The detector 7 is connected to the oscilloscope 6 signal. The oscilloscope 6 can be used to capture the response voltage output by the detector 7. The computer 11 receives and analyzes the voltage data obtained by the oscilloscope 6.

[0033] The photoelectric autocollimator 9 is fixed directly above the incident surface of the reflector subassembly 8 by a lifting column. The laser 12 is connected to the autocollimation light tube of the photoelectric autocollimator 9 by magnetic attraction. The photoelectric autocollimator 9 emits a light beam toward the reflector subassembly 8. The laser 12 emits a light beam perpendicular to the incident surface of the reflector subassembly 8. The light beam emitted by the laser 12 is infrared light with a wavelength of 905nm. Since this infrared wavelength is not convenient for observation, an infrared display card is affixed to the incident surface of the reflector subassembly 8 to facilitate observation of the light spot. The photoelectric autocollimator 9 is equipped with a CCD sensor, which can be used to receive the image data of the light spot reflected by the reflector subassembly 8. The CCD sensor is also connected to the computer 11 by signal. The image data collected by the CCD sensor is received and processed by the computer 11. By analyzing the deviation angle difference between the reflected cross light spot and the center of the optical axis, the deviation angle α of the fixture adapter plate of the four-degree-of-freedom automatic adjustment tool 3 is determined, and the first electric rotary stage and the second electric rotary stage of the electric rotary stage 2 are driven by the motion controller 4 to perform precise adjustment so that the normal of the incident surface of the reflector subassembly 8 remains parallel to the light beam axis.

[0034] A method for adjusting the optimal assembly position of a detector for a pulsed laser receiving system, comprising the following steps:

[0035] S1. During the assembly of the detector 7 in the pulsed laser receiving system, install the detector 7 of the pulsed laser receiver to be modulated on the detector fixture of the four-degree-of-freedom automatic adjustment fixture 3. Then, place the receiver's reflector subassembly 8 on the fixture adapter plate. Power on the computer 11, motion controller 4, motion control card 5, and oscilloscope 6, start the test system, and perform a self-test to ensure that all hardware devices are functioning properly and all motors have returned to their zero positions.

[0036] S2. The laser 12 emits a beam perpendicular to the incident surface of the mirror sub-component 8 through the photoelectric autocollimator 9;

[0037] S3. Based on the data collected by the internal image detection component of the photoelectric autocollimator 9, the deviation angle α of the fixture adapter plate is calculated. Based on the calculation results, the electric rotary table 2 is used to adjust the plane of the fixture adapter plate of the four-degree-of-freedom automatic adjustment tool 3 so that the deviation angle α is lower than the threshold. Based on the testing principle of the photoelectric autocollimator 9 and the principle of geometric optics: when the plane mirror is tilted at an angle α, the angle between the incident light and the normal of the plane mirror is α (which satisfies the law of reflection), and the total deflection angle of the reflected light relative to the original light path direction is 2α. It can be seen that:

[0038]

[0039] Where Δx represents the offset between the returned image and the original target, f represents the focal length of the collimating lens, and α represents the deviation angle of the test platform. Since it is a small angle measurement, α is generally very small, tan 2α ≈ 2α. Substituting it into formula (1) yields:

[0040]

[0041] Since the objective lens position of the photoelectric autocollimator 9 is fixed and the focal length is unchanged, only Δx needs to be known. Assuming that the pixel coordinate difference between the center of the returned cross spot and the center of the optical axis is n, and the size of each pixel is a, then Δx = na, and the deviation angle α is:

[0042]

[0043] S4. Control the four-degree-of-freedom automatic adjustment fixture 3 to move the detector to the initial installation position. When the X-axis translation stage is in the initial installation position, the two edges of the detector extending in the Y direction are equal to the two edges of the reflector subassembly 8 extending in the Y direction. Then, the XY plane electric rotation stage moves the detector until the two edges of the detector extending in the Y direction are parallel to the two edges of the reflector subassembly 8 of the receiver extending in the Y direction. Fix the position of the detector fixture in the X-axis direction, control the four-degree-of-freedom automatic adjustment fixture 3 through the motion control card 5 to adjust, move the detector in the Z and Y-axis directions, obtain the voltage data set through the oscilloscope 6, and determine the maximum corresponding voltage position of the detector in the Z-axis direction. This coordinate position is the optimal installation position of the detector. The detector is clamped by the detector fixture. The four-degree-of-freedom automatic adjustment work 3 controls the movement of the detector fixture through the electric translation stage, thereby adjusting the detector position. The specific steps are as follows:

[0044] S42. Control the Z-axis motorized translation stage to raise the detector by 0.7 mm. Then, control the Y-axis motorized translation stage to move the detector within the Y-axis travel range. During this movement, the detector response voltage output is collected using an oscilloscope according to the set step size to obtain a response voltage data set. This data set is analyzed to record the maximum response voltage and the current Z-axis position coordinates.

[0045] S43. Control the Z-axis motorized translation stage to raise the detector by 0.1 mm. As in step 6, control the Y-axis motorized translation stage to move again, traversing the Y-axis travel range to find the maximum response voltage. Record this maximum value and the current Z-axis position. Repeat this process until the maximum response voltage is found when the Z-axis coordinate is raised by 1.5 mm.

[0046] S44. Based on the nine sets of Z-axis coordinates and maximum response voltage data within the range of 0.7 mm to 1.5 mm obtained in S42 and S43, the Z-axis coordinate at which the maximum response voltage occurs is located. Based on this data set, the Z-axis motorized translation stage is controlled to move to the Z-axis coordinate corresponding to the maximum response voltage.

[0047] S45. Repeat the operation in step S42 at this position to find the Y-axis coordinate corresponding to the maximum value of the response voltage, and finally determine this position as the optimal assembly position of the detector.

Claims

1. A method for bonding, assembling and positioning a laser receiver detector, characterized in that: The following steps are involved: S1. Installation and debugging of a device for bonding, assembling and positioning a laser receiver detector, comprising a computer (11) and an electrically controlled rotary table (2), wherein the electrically controlled rotary table (2) is mounted on a horizontal optical platform (13) and electrically connected to a motion controller (4), wherein a four-degree-of-freedom automatic adjustment tool (4) is fixed to the electrically controlled rotary table (2) via a limit screw and electrically connected to a motion control card (5), wherein the four-degree-of-freedom automatic adjustment tool (4) comprises a test bench and a detector fixture (18), wherein the test bench comprises a Z-axis electric translation table, a Y-axis electric translation table, an X-axis manual translation table, an XY-plane electric rotation table and a fixture adapter plate. A reflector subassembly (8) is placed on a fixture adapter plate, the reflector subassembly (8) is placed on a test bench, a detector (7) is clamped by a detector fixture and electrically connected to an oscilloscope (6) to obtain a response voltage, a photoelectric autocollimator (9) is fixed directly above the incident surface of the reflector subassembly (8) through a lifting column, an image detection component is provided in the photoelectric autocollimator, and the image detection component is connected to a computer, a laser (12) is connected to the autocollimation light tube of the photoelectric autocollimator (9) through a magnetic attraction method and emits a light beam directed toward the reflector subassembly (8), and the light beam emitted by the laser (12) is perpendicular to the incident surface of the reflector subassembly (8); S2. The laser (12) emits a light beam perpendicular to the incident surface of the mirror subassembly (8); S3. Based on the data collected by the internal image detection component of the photoelectric autocollimator (9), the deviation angle α of the fixture adapter plate is determined, and the fixture adapter plate of the four-degree-of-freedom automatic adjustment tool (4) is adjusted using an electric rotary table (2); S4. Control the four-degree-of-freedom automatic adjustment fixture (3) to make adjustments, obtain the voltage data set through the oscilloscope (6), and determine the maximum corresponding voltage position of the detector in the three directions of XYZ. The three-axis coordinate position is the optimal installation position of the detector.

2. The method for bonding, assembling, adjusting and positioning a laser receiver detector according to claim 1, characterized in that: In step S3, the deflection angle α is: Wherein, f represents the focal length of the objective lens of the photoelectric autocollimator (9); n is the pixel coordinate difference between the center of the cross spot after reflection and the center of the beam axis; a is the pixel size.

3. The method for bonding, assembling, adjusting and positioning a laser receiver detector according to claim 1, characterized in that: An infrared display card is attached to the incident surface of the reflector subassembly (8) for observing the light spot.

4. The method for bonding, assembling, adjusting and positioning a laser receiver detector according to claim 1, characterized in that: The optical platform (1) is made of ferromagnetic stainless steel, and the flatness is not greater than 0.

1.

5. The method for bonding, assembling, adjusting and positioning a laser receiver detector according to claim 1, characterized in that: The four-degree-of-freedom automatic adjustment tool (4) can adjust the displacement in the three directions of XYZ and the rotation in the XY plane.

6. The method for bonding, assembling, adjusting and positioning a laser receiver detector according to claim 1, characterized in that: Step S4 includes: S41. Move the detector in the X-axis direction to the initial adjustment position, so that the center of the detector is equidistant from the two edges of the reflector subassembly extending in the Y-direction. Move the detector on the XY-plane motorized rotary stage until the two edges of the detector extending in the Y-direction are parallel to the two edges of the receiver's reflector subassembly extending in the Y-direction. Secure the detector fixture in the X-axis position. S42. Control the Z-axis motorized translation stage to raise the detector by 0.7 mm. Then, control the Y-axis motorized translation stage to move the detector within the Y-axis travel range. During this movement, the detector response voltage output is collected using an oscilloscope according to the set step size to obtain a response voltage data set. This data set is analyzed to record the maximum response voltage and the current Z-axis position coordinates. S43. Control the Z-axis motorized translation stage to raise the detector by 0.1 mm. As in step 6, control the Y-axis motorized translation stage to move again, traversing the Y-axis travel range to find the maximum response voltage. Record this maximum value and the current Z-axis position. Repeat this process until the maximum response voltage is found when the Z-axis coordinate is raised by 1.5 mm. S44. Based on the data sets of multiple sets of Z-axis coordinates and maximum response voltages in the range of 0.7 mm to 1.5 mm obtained in S42 and S43, the Z-axis coordinate at which the maximum response voltage is located is located. Based on the data set, the Z-axis electric translation stage is controlled to move to the Z-axis coordinate corresponding to the maximum response voltage. S45. Repeat the operation in step S42 at this position to find the Y-axis coordinate corresponding to the maximum value of the response voltage, and finally determine this position as the optimal assembly position of the detector.

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