A rotation angle measurement device and method for MEMS array

Abstract

This application discloses a rotation angle measurement device and method for a MEMS array, relating to the field of MEMS measurement. The device and method include: a laser light source disposed on one side of an optical platform; an optical platform for placing and moving the MEMS array; a projection plane disposed above the other side of the optical platform and capable of moving up and down; an industrial camera disposed in correspondence with the projection plane; a control unit connected to the optical platform, the MEMS array, and the industrial camera; and a control unit connected to the optical platform, the MEMS array, and the industrial camera. The control unit rotates the mirror to be measured in a certain direction by changing the voltage of the pin corresponding to the mirror to be measured in the MEMS array. The control unit also controls the industrial camera to capture an image of the projection plane and mark the coordinates of the light spot on the image, thereby determining the correspondence between different pin voltages and the light spot coordinates, and ultimately plotting a voltage-angle response curve. This application does not require precise calibration of the angle of the incident light and can automatically and accurately measure the rotation angle of the MEMS array even when the angle of change is very small.

Description

Technical Field

[0001] The present application relates to the field of MEMS measurement technology, and in particular to a rotation angle measurement device and method for a MEMS array. Background Art

[0002] A MEMS array refers to multiple mirrors controlled by a micro-electromechanical system (MEMS), each with multiple rotation axes and directions. In devices that use electrical signals to control optical light paths, the rotation angle of the MEMS array is a critical operating parameter, affecting the performance parameters of optical switching devices based on MEMS arrays, such as the optical path control range, control parameters, and specification consistency.

[0003] Currently, the rotation angle measurement of MEMS arrays usually requires measuring the rotation angle of each mirror in the MEMS array separately. The basic process is to have a light beam incident on the top of the MEMS array. After the mirror in the MEMS array rotates, the rotation angle of the mirror is manually determined based on the change in the position of the reflected light spot. Although the above method can achieve the measurement of the rotation angle, it must accurately calibrate the angle of the incident light so that it can be completely perpendicular to the mirror of the MEMS array. When the rotation angle of the MEMS array is small, the light spot formed by the incident light reflected by the mirror is likely to be blocked by the light source, making it impossible to further determine the rotation angle based on the change in the light spot position. At the same time, the above process cannot achieve automatic measurement of the MEMS array. Summary of the Invention

[0004] The purpose of this application is to provide a rotation angle measurement device and method for a MEMS array, which does not require precise calibration of the angle of the incident light and can automatically and accurately measure its rotation angle even when the angle of the MEMS array changes slightly.

[0005] To achieve the above objectives, this application provides the following solutions.

[0006] In a first aspect, the present application provides a rotation angle measurement device for a MEMS array, wherein the rotation angle measurement device for a MEMS array comprises: an optical platform, a laser light source, a microscope, a projection plane, an industrial camera, and a control unit.

[0007] The optical platform is used to place and move the MEMS array; the MEMS array has two rotation axes and four rotation directions.

[0008] The laser light source is arranged on one side of the optical platform; the laser light source is used to provide incident light to the MEMS array.

[0009] The microscope is arranged directly above the optical platform; the microscope is used to calibrate the incident light and the position of the mirror in the MEMS array, and to observe the connection status between the MEMS array and the control unit.

[0010] The projection plane is arranged above the other side of the optical platform and can move up and down; the projection plane is used to display the light spot formed after the incident light is reflected by the mirror surface.

[0011] The industrial camera is arranged corresponding to the projection plane; the industrial camera is used to capture the light spot on the projection plane by shooting an image.

[0012] The control unit is connected to the optical platform, the MEMS array and the industrial camera respectively; the control unit is used to: control the movement of the optical platform; change the pin voltage corresponding to the mirror to be measured in the MEMS array to make the mirror to be measured rotate in a rotation direction, and at the same time control the industrial camera to capture an image of the projection plane and mark the spot coordinates on the image, and determine the correspondence between different pin voltages and spot coordinates; calculate the spot movement distance corresponding to different pin voltages according to the spot coordinates corresponding to different pin voltages, the coordinates of the initial spot and the pixel parameters, and substitute the distance parameters and the spot movement distance corresponding to the different pin voltages into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, determine the response angle of the mirror to be measured corresponding to each pin voltage and draw a voltage-angle response curve; obtain the voltage-angle response curves of all mirrors in the MEMS array in four rotation directions, and complete the rotation angle measurement of the MEMS array.

[0013] In a second aspect, the present application further provides a rotation angle measurement method for a MEMS array, which is applied to the rotation angle measurement device for a MEMS array described in the first aspect. The rotation angle measurement method for a MEMS array is as follows.

[0014] A MEMS array is placed on an optical platform, the optical platform is moved by a control unit, and the MEMS array is observed through a microscope so that the center point of the mirror to be measured in the MEMS array is aligned with the incident point of the incident light. After the incident light is reflected by the mirror to be measured, an initial light spot is formed on the projection plane. The mirror to be measured is any mirror in the MEMS array. The incident direction of the incident light is perpendicular to the current rotation axis of the mirror to be measured, and the incident angle of the incident light is an acute angle.

[0015] Measure distance parameters and calibrate industrial cameras to obtain pixel parameters.

[0016] The control unit is used to change the pin voltage corresponding to the mirror to be tested so that the mirror to be tested rotates in a rotation direction. At the same time, the industrial camera is controlled to capture an image of the projection plane and mark the coordinates of the light spot on the image to determine the correspondence between different pin voltages and the coordinates of the light spot.

[0017] A control unit is used to calculate the light spot movement distance corresponding to different pin voltages based on the light spot coordinates corresponding to different pin voltages, the coordinates of the initial light spot, and the pixel parameters. The distance parameters and the light spot movement distance corresponding to different pin voltages are substituted into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, and the response angle of the mirror to be measured corresponding to each pin voltage is determined and a voltage-angle response curve is plotted.

[0018] The control unit is used to adjust the pin voltage corresponding to the mirror to be tested, and the voltage-angle response curves of the mirror to be tested in different rotation directions are obtained respectively.

[0019] Repeat the above steps to obtain the voltage-angle response curves of all mirrors in the MEMS array in four rotation directions, and complete the rotation angle measurement of the MEMS array.

[0020] According to the specific embodiments provided in this application, this application discloses the following technical effects.

[0021] First, the main calculation relationship of angle measurement in this application is composed of a triangle composed of distance parameters, which depends on the correspondence between the sides and angles in the triangle. The angle of the incident light does not participate in the calculation, so there is no need to accurately calibrate the angle of incidence. Secondly, this application sets the laser light source on one side of the optical platform and sets a projection plane for displaying the reflected light spot on the other side. Because the projection plane can move up and down, the moving distance of the light spot can be magnified by raising the projection plane, and then the change in the position of the light spot can be effectively judged when the angle of the MEMS array changes slightly. At the same time, this application also sets an industrial camera corresponding to the projection plane, which can also accurately capture the slight angle changes of the MEMS array. In addition, in this application, the control unit is connected to the optical platform, MEMS array and industrial camera respectively, so that it can realize the movement control of the optical platform and the change of the MEMS array driving voltage. At the same time, it can automatically generate all the voltage-angle response curves of the MEMS array according to the data captured by the industrial camera, thereby realizing automatic measurement of the rotation angle of the MEMS array. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 A schematic diagram of the structure of a rotation angle measurement device for a MEMS array provided in an embodiment of the present application.

[0024] Figure 2 This is a flow chart of a method for measuring the rotation angle of a MEMS array provided in an embodiment of the present application.

[0025] Figure 3 This is a diagram of the optical path effect produced by rotating the mirror to be tested around the Y-axis provided in an embodiment of the present application.

[0026] Figure 4 This is a diagram showing the main optical path produced by rotating the mirror to be tested around the X-axis provided in an embodiment of the present application.

[0027] Figure 5 This is a diagram of the left-view optical path effect produced by rotating the mirror to be tested around the X-axis provided in an embodiment of the present application.

[0028] Reference numerals: optical platform-1, laser light source-2, microscope-3, projection plane-4, industrial camera-5. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] Existing methods for measuring rotation angles require precise calibration of the incident light so that it is completely perpendicular to the incident mirror surface, that is, the incident angle must be precisely calibrated; when the MEMS array rotates at a small angle, the reflected light spot is blocked by the light source, making it impossible to measure extremely small angles; because the light source is installed above the MEMS array, it is no longer possible to observe from directly above and determine whether the MEMS array is properly connected to the control unit; due to the lack of sensor application, existing methods cannot perform automated measurement of MEMS arrays.

[0031] In order to accurately and effectively measure the rotation angle of a MEMS array, a reliable rotation angle measurement device and method are proposed for each rotation direction of each mirror in a MEMS array with two rotation axes X and Y and four rotation directions of X+, X-, Y+, and Y-. The measurement error compensation is fully considered during the measurement process.

[0032] The purpose of this application is to provide a rotation angle measurement device and method for a MEMS array, which does not require precise calibration of the angle of the incident light and can automatically and accurately measure its rotation angle even when the angle of the MEMS array changes slightly.

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] Example 1

[0035] like Figure 1 As shown, this embodiment provides a rotation angle measuring device for a MEMS array, which includes: an optical platform 1, a laser light source 2, a microscope 3, a projection plane 4, an industrial camera 5 and a control unit (not shown in the figure).

[0036] The optical platform 1 is used to place and move the MEMS array; the MEMS array has two rotation axes (ie, an X rotation axis and a Y rotation axis) and four rotation directions (ie, an X+ rotation direction, an X- rotation direction, a Y+ rotation direction, and a Y- rotation direction).

[0037] The laser light source 2 is disposed on one side of the optical platform 1 ; the laser light source 2 is used to provide incident light to the MEMS array.

[0038] Microscope 3 is set directly above optical platform 1; microscope 3 is used to calibrate the position of the incident light and the mirror in the MEMS array (that is, the center point of the mirror to be measured in the MEMS array is aligned with the incident point of the incident light), and to observe the connection status between the MEMS array and the control unit (that is, whether the MEMS array is normally connected to the control unit).

[0039] Projection plane 4 is set above the other side of the optical platform 1 and can be moved up and down (when measuring very small angle changes, the light spot movement distance can be magnified by raising projection plane 4); projection plane 4 is used to display the light spot formed after the incident light is reflected by the mirror.

[0040] The industrial camera 5 is arranged corresponding to the projection plane 4; the industrial camera 5 is used to capture the light spot on the projection plane by shooting an image.

[0041] The control unit is connected to the optical platform 1, the MEMS array and the industrial camera 5 respectively; the control unit is used to: control the movement of the optical platform 1; change the pin voltage corresponding to the mirror to be measured in the MEMS array so that the mirror to be measured rotates in a rotation direction, and at the same time control the industrial camera 5 to capture an image of the projection plane and mark the coordinates of the light spot on the image, and determine the correspondence between different pin voltages and the light spot coordinates; calculate the light spot movement distance corresponding to different pin voltages based on the light spot coordinates corresponding to different pin voltages, the coordinates of the initial light spot (i.e., the light spot formed by the reflection of the incident light by the mirror at zero voltage) and pixel parameters, and substitute the distance parameters and the light spot movement distance corresponding to different pin voltages into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, determine the response angle of the mirror to be measured corresponding to each pin voltage and draw a voltage-angle response curve; obtain the voltage-angle response curves of all mirrors in the MEMS array in four rotation directions, and complete the rotation angle measurement of the MEMS array.

[0042] As a preferred embodiment, the industrial camera 5 and the laser light source 2 are arranged on both sides of the optical platform 1; the industrial camera 5 is arranged directly below the projection plane 4, and the area of ​​the projection plane 4 (large enough) is larger than the shooting range of the industrial camera 5.

[0043] As a preferred embodiment, the optical platform 1, industrial camera 5 and control unit are placed horizontally on a table; the projection plane 4 is fixed to the edge of the table via a first bracket (i.e., a U-shaped bracket, one end of which is fixed to the edge of the table and the other end supports the projection plane 4); the laser light source 2 is supported on the table via a second bracket (i.e., a tripod bracket); and the microscope 3 is fixed directly above the optical platform 1 using its own bracket structure.

[0044] Based on the above features, the rotation angle measurement device for the MEMS array in this embodiment can, with the assistance of the control unit, obtain the rotation angle of the MEMS array under multiple target voltages through multiple measurements, and then obtain the key parameters of MEMS control, namely the voltage-angle response curve.

[0045] Example 2

[0046] like Figure 2 As shown, this embodiment provides a rotation angle measurement method for a MEMS array. The rotation angle measurement method for a MEMS array is applied to the above-mentioned rotation angle measurement device for a MEMS array. The rotation angle measurement method for a MEMS array is as follows.

[0047] Step S1: Place the MEMS array on an optical platform, use a control unit to move the optical platform, and observe the MEMS array through a microscope so that the center point of the mirror to be measured in the MEMS array is aligned with the incident point of the incident light. After the incident light is reflected by the mirror to be measured, an initial light spot is formed on the projection plane.

[0048] In this embodiment, the mirror to be measured is any mirror in the MEMS array. The number of mirrors to be measured is equal to the number of mirrors in the MEMS array. The incident light emitted by the laser light source must meet the following requirements: the incident direction of the incident light is perpendicular to the current rotation axis of the mirror to be measured, and the incident angle of the incident light is acute. The initial light spot is obtained when no voltage is applied to the MEMS array, so it is also called a zero-voltage light spot.

[0049] Step S2: Measure distance parameters and calibrate the industrial camera to obtain pixel parameters.

[0050] In this embodiment, the distance parameter measurement and the calibration of the industrial camera are completed manually. The distance parameters to be measured include: the vertical distance between the incident point and the projection plane , the distance between the incident point and the initial light spot , and the distance between the vertical point of the incident point on the projection plane and the initial spot ,in In addition, the process of calibrating the industrial camera to obtain pixel parameters is as follows.

[0051] The first step is to post a ruler with a fixed length and width on the projection plane within the shooting range of the industrial camera; the length and width of the ruler are aligned with the length and width of the image captured by the industrial camera. In this embodiment, the long side of the ruler is mm, wide side mm.

[0052] The second step is to turn off the laser light source, use an industrial camera to take an image and determine the resolution of the image. In this embodiment, the resolution of the image is 1920×1080.

[0053] The third step is to manually mark the pixel units corresponding to the long side and wide side of the ruler in the image. The corresponding pixel unit is , the wide side of the ruler The corresponding pixel unit is .

[0054] The fourth step is to calculate the pixel parameters according to the length and width of the ruler, the resolution of the image, and the pixel units corresponding to the long side and the wide side of the ruler in the image. In this embodiment, the pixel parameters include: the long side of the ruler Corresponding to the image The distance between pixels (mm / pixel), wide side of the ruler Corresponding to the image The distance between pixels (mm / pixel), satisfy: , satisfy: .

[0055] Step S3: Use the control unit to change the pin voltage corresponding to the mirror to be tested, so that the mirror to be tested rotates in a rotation direction. At the same time, control the industrial camera to capture an image of the projection plane and mark the coordinates of the light spot on the image to determine the correspondence between different pin voltages and the coordinates of the light spot.

[0056] In this embodiment, when determining the correspondence between different pin voltages and the light spot coordinates, it is necessary to ensure that the mirror to be measured first rotates in one rotational direction. After the measurement of that rotational direction is completed, it is switched to the other rotational direction. The rotational direction cannot be changed arbitrarily during the process. Specifically, the control unit gradually increases the pin voltage of the mirror to be measured, causing it to rotate in one axial direction, thereby causing the light spot to shift on the projection plane. After each voltage change, an image is captured using an industrial camera. The upper left corner of the image is used as the origin, and the light spot coordinates on the image are marked through image recognition. After multiple voltage changes and image marking, a correspondence between the pin voltage and the light spot coordinates is obtained.

[0057] Step S4: Utilize the control unit to calculate the spot movement distance corresponding to different pin voltages based on the spot coordinates corresponding to different pin voltages, the coordinates of the initial spot, and the pixel parameters, and substitute the distance parameters and the spot movement distance corresponding to different pin voltages into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, determine the response angle of the mirror to be measured corresponding to each pin voltage, and draw a voltage-angle response curve.

[0058] In this embodiment, it is assumed that the coordinates of the initial light spot (zero voltage light spot) are , the coordinates of the light spot under a certain voltage are , then the light spot moves a distance satisfy: For different rotation directions, this embodiment determines different angle calculation formulas, that is, the angle calculation formula corresponding to the Y+ rotation direction is as follows.

[0059] .

[0060] Where, Indicates the measured angle of the mirror to be measured in the Y+ rotation direction.

[0061] The angle calculation formula corresponding to the Y-rotation direction is as follows.

[0062] .

[0063] Where, Indicates the measured angle of the mirror to be measured in the Y-rotation direction.

[0064] The angle calculation formula corresponding to X+rotation direction is as follows.

[0065] .

[0066] The angle calculation formula corresponding to the X-rotation direction is as follows.

[0067] .

[0068] Where, Indicates the measurement angle of the mirror to be measured in the X+ rotation direction, Indicates the measured angle of the mirror to be measured in the X-rotation direction. The angle calculation formulas in the X+ rotation direction and the X-rotation direction are essentially the same.

[0069] Specifically, if Figure 3 As shown, when the mirror to be measured rotates around the Y axis, the incident light is perpendicular to the Y axis. When a voltage is applied to the Y-direction of the mirror to be measured, the distance the light spot moves on the projection plane is When a voltage is applied to the Y+ direction of the mirror to be measured, the distance the light spot moves on the projection plane is , then the angle of rotation of the mirror to be measured around the Y+ rotation direction is and the angle of rotation around the Y-direction The following relationship is satisfied.

[0070] .

[0071] .

[0072] like Figure 4 As shown, when the mirror to be measured rotates around the X axis, the incident light is perpendicular to the X axis. When a voltage is applied to the X+ direction of the mirror to be measured, the distance the light spot moves on the projection plane is .Will Figure 4 in After projecting to the left view, we get Figure 5 in ,Right now , the angle of rotation of the mirror to be measured around the X+ rotation direction The following relationship is satisfied.

[0073] .

[0074] Since the X-rotation direction is related to the X+rotation direction The straight lines where the light spots are located are symmetrical. Although the light spots move in opposite directions, the angle relationship is consistent, so the angle calculation formulas in the X- and X+ rotation directions are the same.

[0075] Step S5: using the control unit to adjust the pin voltage corresponding to the mirror to be tested, and respectively obtain the voltage-angle response curves of the mirror to be tested in different rotation directions.

[0076] In this embodiment, by continuously executing the above steps S3 to S4, the voltage-angle response curves of the mirror to be tested in the four rotation directions of X+, X-, Y+ and Y- can be obtained.

[0077] Step S6: Repeat the above steps (S1 to S5) to obtain the voltage-angle response curves of all mirrors in the MEMS array in the four rotation directions, and complete the rotation angle measurement of the MEMS array.

[0078] In summary, this application mainly has the following advantages.

[0079] (1) First, the main calculation relationship of angle measurement is given by 、 、 The triangle is composed of three components, so there is no need to calibrate the incident angle precisely.

[0080] (2) Secondly, since the measuring light path is unobstructed, the measuring device can measure very small angle changes within the angle change range of the MEMS array (for example, 0° to 10°). The measuring device can also amplify the moving distance of the light spot by raising the projection plane, and improve the ability to capture small angle changes of the MEMS array by improving the resolution of the industrial camera.

[0081] (3) Moreover, the measuring device can place a microscope above the MEMS array to observe and calibrate the shape and position of the MEMS array, and at the same time observe and determine whether the MEMS array is normally connected to the control unit.

[0082] (4) Finally, after the parameters are calibrated, the measurement process of the measuring device is completely controlled by the control unit, so that automated measurement can be achieved, and all voltage-angle response curves of a MEMS array can be measured at one time.

[0083] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0084] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A rotation angle measurement device for a MEMS array, characterized in that: The rotation angle measurement device for the MEMS array includes: an optical platform, a laser light source, a microscope, a projection plane, an industrial camera and a control unit; The optical platform is used to place and move the MEMS array; the MEMS array has two rotation axes and four rotation directions; the MEMS array has two rotation axes, X and Y, and is divided into four rotation directions of X+, X-, Y+ and Y-; The laser light source is arranged on one side of the optical platform; the laser light source is used to provide incident light to the MEMS array; The microscope is arranged directly above the optical platform; the microscope is used to calibrate the position of the incident light and the mirror in the MEMS array, and to observe the connection status between the MEMS array and the control unit; The projection plane is arranged above the other side of the optical platform and can move up and down; the projection plane is used to display the light spot formed after the incident light is reflected by the mirror surface; The industrial camera is arranged corresponding to the projection plane; the industrial camera is used to capture the light spot on the projection plane by shooting an image; The control unit is connected to the optical platform, the MEMS array and the industrial camera respectively; the control unit is used to: control the movement of the optical platform; change the pin voltage corresponding to the mirror to be measured in the MEMS array to make the mirror to be measured rotate in a rotation direction, and at the same time control the industrial camera to capture an image of the projection plane and mark the spot coordinates on the image, and determine the correspondence between different pin voltages and spot coordinates; calculate the spot movement distance corresponding to different pin voltages according to the spot coordinates corresponding to different pin voltages, the coordinates of the initial spot and the pixel parameters, and substitute the distance parameters and the spot movement distance corresponding to the different pin voltages into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, determine the response angle of the mirror to be measured corresponding to each pin voltage and draw a voltage-angle response curve; obtain the voltage-angle response curves of all mirrors in the MEMS array in four rotation directions, and complete the rotation angle measurement of the MEMS array.

2. The rotation angle measurement device for a MEMS array according to claim 1, characterized in that: The industrial camera and the laser light source are arranged on both sides of the optical platform; the industrial camera is arranged directly below the projection plane, and the area of ​​the projection plane is larger than the shooting range of the industrial camera.

3. The rotation angle measuring device for a MEMS array according to claim 1, characterized in that: The optical platform, the industrial camera and the control unit are placed horizontally on a desktop; the projection plane is fixed on the edge of the desktop via a first bracket; and the laser light source is supported on the desktop via a second bracket.

4. A method for measuring the rotation angle of a MEMS array, characterized in that: The rotation angle measurement method for a MEMS array is applied to the rotation angle measurement device for a MEMS array according to any one of claims 1 to 3, and the rotation angle measurement method for a MEMS array comprises the following steps: Step S1: placing a MEMS array on an optical platform, moving the optical platform using a control unit, and observing the MEMS array through a microscope so that the center point of the mirror to be measured in the MEMS array is aligned with the incident point of the incident light, and the incident light is reflected by the mirror to be measured to form an initial light spot on the projection plane; the mirror to be measured is any mirror in the MEMS array; the incident direction of the incident light is perpendicular to the current rotation axis of the mirror to be measured, and the incident angle of the incident light is an acute angle; Step S2: measuring distance parameters and calibrating the industrial camera to obtain pixel parameters; the distance parameters include: the vertical distance between the incident point and the projection plane, the distance between the incident point and the initial light spot, and the distance between the vertical point of the incident point on the projection plane and the initial light spot; Step S3: using a control unit to change the pin voltage corresponding to the mirror to be tested, so that the mirror to be tested rotates in a rotation direction, and at the same time controlling an industrial camera to capture an image of the projection plane and mark the coordinates of the light spot on the image, and determining the correspondence between different pin voltages and the light spot coordinates; Step S4: Using the control unit, calculate the spot movement distance corresponding to different pin voltages based on the spot coordinates corresponding to different pin voltages, the coordinates of the initial spot, and the pixel parameters, and substitute the distance parameters and the spot movement distance corresponding to different pin voltages into the angle calculation formula corresponding to the current rotation direction of the mirror to be measured, determine the response angle of the mirror to be measured corresponding to each pin voltage, and draw a voltage-angle response curve; the angle calculation formula corresponding to the Y+ rotation direction is: ； The angle calculation formula corresponding to the Y-rotation direction is: ； The angle calculation formula corresponding to X+rotation direction is: ； The angle calculation formula corresponding to the X-rotation direction is: ； Where, Indicates the measured angle of the mirror to be measured in the Y+ rotation direction, represents the vertical distance between the incident point and the projection plane, represents the distance between the incident point and the initial light spot, Indicates the distance between the vertical point of the incident point on the projection plane and the initial light spot, Indicates the distance the light spot moves, Indicates the measurement angle of the mirror to be measured in the Y-rotation direction, Indicates the measurement angle of the mirror to be measured in the X+ rotation direction, Indicates the measurement angle of the mirror to be measured in the X-rotation direction; Step S5: using a control unit to adjust the pin voltage corresponding to the mirror to be tested, and respectively obtain voltage-angle response curves of the mirror to be tested in different rotation directions; Repeat steps S1 to S5 to obtain voltage-angle response curves of all mirrors in the MEMS array in four rotation directions, thereby completing the rotation angle measurement of the MEMS array.

5. The method for measuring the rotation angle of a MEMS array according to claim 4, wherein: The calibrating of the industrial camera to obtain pixel parameters specifically includes: Posting a ruler with a certain length and width on a projection plane within the shooting range of the industrial camera; the length and width of the ruler are aligned with the length and width of the image captured by the industrial camera; Turning off the laser light source, taking an image with the industrial camera, and determining the resolution of the image; Manually mark the pixel units corresponding to the long side and the wide side of the ruler in the image; Pixel parameters are calculated according to the length and width of the ruler, the resolution of the image, and the pixel units corresponding to the long side and the wide side of the ruler in the image.

Images