An aperture motion closed loop control system

Abstract

The application discloses an aperture motion closed-loop control system, which comprises a fixed seat, a movable turntable, a blade moved by the movable turntable, a blade guide for guiding the movement of the blade to form different aperture diaphragms, a VCM motor for controlling the rotation of the movable turntable relative to the fixed seat, and a detection mechanism for detecting the rotation angle of the movable turntable, wherein the detection mechanism comprises a first fixed grating, a second fixed grating, a movable grating, a first photoelectric sensor, a second photoelectric sensor and a main controller. According to the application, the VCM motor and the grating can be arranged in an arc shape according to the aperture structure, the occupied space is small, and the design structure of the aperture is very suitable. The angle detection can be realized by using two light sources. The VCM motor is controlled according to the calculated rotation angle by the main controller, the closed-loop control of the aperture motion is realized, the control precision is improved, the automatic deviation correction is realized, the resistance to external interference is improved, and the aperture performance is improved.

Description

Technical Field

[0001] This invention relates to the field of displacement detection technology, and more specifically to a closed-loop control system for aperture motion. Background Technology

[0002] Currently, camera apertures are primarily controlled via open-loop control using stepper motors, or closed-loop control using magnetic encoders or coaxial encoders. However, in practical applications, open-loop control suffers from low accuracy, lacks automatic correction capabilities, has low resistance to external interference, and the stepper motor's slow response and low speed limit restrict aperture performance. On the other hand, using coaxial or magnetic encoders is space-consuming, has a fixed design, and is unsuitable for products with limited structural space. Furthermore, ordinary coaxial and magnetic encoders have limited accuracy, posing significant drawbacks for short-distance, high-precision displacement detection. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by providing an aperture motion closed-loop control system, which can achieve closed-loop control of aperture motion, improve resistance to external interference, and has a flexible installation structure with a small footprint.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A closed-loop control system for aperture motion includes a fixed base, a movable turntable, blades moved by the movable turntable, blade guides for guiding the movement of the blades to form apertures of different apertures, a VCM motor for controlling the rotation of the movable turntable relative to the fixed base, and a detection mechanism for detecting the rotation angle of the movable turntable. The detection mechanism includes a first fixed grating, a second fixed grating, a movable grating, a first photoelectric sensor, a second photoelectric sensor, and a main controller. The movable grating is fixedly mounted on the movable turntable. The first photoelectric sensor has a first light source emitting end and a first light source receiving end for receiving light emitted by the first light source emitting end after passing through the first fixed grating and the movable grating. The second photoelectric sensor has a second light source emitting end and a second light source receiving end for receiving light emitted by the second light source emitting end after passing through the second fixed grating and the movable grating. The VCM motor, the first light source receiving end, and the second light source receiving end are all connected to the main controller.

[0006] As a preferred embodiment, the first photoelectric sensor, the second photoelectric sensor, the first fixed grating, and the second fixed grating are all fixedly mounted on a fixed base, and the first fixed grating and the second fixed grating are sequentially arranged on the same side of the movable grating along the rotation direction of the movable turntable.

[0007] As a preferred embodiment, the first fixed grating and the second fixed grating are equidistant from the movable grating, and the first fixed grating and the second fixed grating are integrally connected.

[0008] As a preferred embodiment, the first fixed grating has a plurality of identical first light-transmitting slots arranged in an arc shape, the second fixed grating has a plurality of identical second light-transmitting slots arranged in an arc shape, and the movable grating has a plurality of identical third light-transmitting slots arranged in an arc shape, wherein the spacing between the first light-transmitting slots, the second light-transmitting slots, and the third light-transmitting slots is the same.

[0009] As a preferred embodiment, the number of the first and second light-transmitting slots is the same, the number of the third light-transmitting slots is greater than the number of the first and second light-transmitting slots, and the width of the first, second, and third light-transmitting slots is the same.

[0010] As a preferred embodiment, the VCM motor includes a motor bracket, a coil, and a magnet that generates an Ampere force in the coil when the coil is energized. The magnet is located on both sides of the magnetic pole boundary line, forming two magnetic field regions with different magnetic field directions. The coil has coil segments located in the two magnetic field regions respectively.

[0011] As a preferred embodiment, the movable turntable is provided with spaced-out locking blocks, and the coil is fixedly wound around the outside of the locking blocks.

[0012] As a preferred embodiment, the light signal intensity received by the first light source receiver is 90 degrees out of phase with the light signal intensity received by the second light source receiver.

[0013] As a preferred embodiment, the light emitted by the first light source and the second light source emitters have the same light intensity and do not interfere with each other.

[0014] As a preferred option, the closed-loop control process is as follows:

[0015] (1) Make the first light source emitting end and the second light source emitting end emit light of constant intensity. The VCM motor controls the rotation of the movable turntable. The movable grating moves with the movable turntable. The first light source receiving end receives the light from the first light source passing through the first fixed grating and the movable grating. The second light source receiving end receives the light from the second light source passing through the second fixed grating and the movable grating.

[0016] (2) The main controller converts the light intensity signals received by the first light source receiver and the second light source receiver into periodically changing electrical signals y1(x) and y2(x), respectively. The phase difference between the electrical signals y1(x) and y2(x) is 90 degrees.

[0017] (3) The main controller divides the electrical signals y1(x) and y2(x) within a single cycle into four parts. If y1(x) is less than or equal to 0 and y2(x) is less than 0, this is recorded as the first part. If y1(x) is less than or equal to 0 and y2(x) is greater than or equal to 0, this is recorded as the second part. If y1(x) is greater than 0 and y2(x) is greater than or equal to 0, this is recorded as the third part. If y1(x) is greater than 0 and y2(x) is less than 0, this is recorded as the fourth part. Then, different operations are performed on each part:

[0018] Part 1: y = ((2*y2(x)min-y2(x)+y1(x))+y2(x)min);

[0019] Part Two: y = (y2(x) + y1(x) + y2(x)min);

[0020] Part 3: y = ((2*y1(x)max-y1(x)+y2(x))+y2(x)min);

[0021] Part 4: y = ((2*y1(x)max - y1(x) - y2(x)) + y2(x)min);

[0022] Here, y2(x)min refers to the minimum value of y2(x), which is equal to y1(x)min, and y1(x)max refers to the maximum value of y1(x), which is equal to y2(x)max. Combining these four parts yields the offset value y of y1(x) and y2(x) that changes periodically with the movement of the moving grating, and the offset value y within the same period is directly proportional to the rotation angle of the moving grating.

[0023] (4) The angle of rotation of the active grating relative to the origin is calculated according to the formula A=nθ+ykθ, where n is the number of cycles of the offset value y, θ is the angle of rotation of the active grating corresponding to one cycle of the offset value y, y is the offset value in the current cycle calculated in step (3), and k is the proportional coefficient between the offset value y and θ.

[0024] (5) The main controller controls the VCM motor to work based on the angle calculated in step (4).

[0025] Compared with existing technologies, this invention has significant advantages and beneficial effects. Specifically, the VCM motor and grating can be set to an arc shape according to the aperture structure, occupying little space and perfectly matching the aperture design structure. Angle detection can be achieved by using two light sources, resulting in low energy consumption and small space occupation. By converting the two optical signals into electrical signals, and then converting the electrical signals of the two light sources into an offset value proportional to the angle according to the atan2 function concept, the actual rotation angle can be obtained quickly and accurately. Then, the main controller controls the VCM motor according to the calculated rotation angle to achieve closed-loop control of the aperture movement, improving control accuracy, enabling automatic correction, and enhancing resistance to external interference. By placing the coil in the VCM motor in two magnetic fields with different magnetic field directions, the coil receives a greater magnetic force, making the VCM motor respond faster than the stepper motor, ensuring rapid acquisition of the desired aperture size and improving aperture performance.

[0026] To more clearly illustrate the structural features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the assembly structure according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the connection structure between the movable turntable and the VCM motor according to an embodiment of the present invention;

[0029] Figure 3 This is an exploded view of the movable turntable and VCM motor according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the detection mechanism according to an embodiment of the present invention;

[0031] Figure 5 This is an exploded structural diagram of a VCM motor according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the structure of a VCM motor according to another embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the detection principle of an embodiment of the present invention;

[0034] Figure 8 This is a signal curve diagram of an embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the offset value segmentation sorting according to an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached diagram:

[0037] 10. Fixed base; 20. Movable turntable; 21. Locking block.

[0038] 30. Blade guide; 40. VCM motor; 41. Motor bracket

[0039] 42. Coil; 43. First magnet; 44. Second magnet

[0040] 50. First photoelectric sensor; 51. First light source transmitter; 52. First light source receiver.

[0041] 60. Second photoelectric sensor; 61. Second light source transmitter; 62. Second light source receiver.

[0042] 70. First fixed grating; 71. First light-transmitting groove; 80. Second fixed grating

[0043] 81, second light-transmitting groove; 90, movable grating; 91, third light-transmitting groove. Detailed Implementation

[0044] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the indicated position or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] like Figure 1-7As shown, this invention proposes an aperture motion closed-loop control system, including a fixed base 10, a movable turntable 20, blades (not shown) moved by the movable turntable 20, a blade guide 30 for guiding the movement of the blades to form apertures of different diameters, and also includes a VCM motor 40 for controlling the rotation of the movable turntable 20 relative to the fixed base 10, and a detection mechanism for detecting the rotation angle of the movable turntable 20. The detection mechanism includes a first fixed grating 70, a second fixed grating 80, a movable grating 90, a first photoelectric sensor 50, a second photoelectric sensor 60, and a main controller (not shown). (As shown), the movable grating 90 is fixedly mounted on the movable turntable 20. The first photoelectric sensor 50 has a first light source emitting end 51 and a first light source receiving end 52 for receiving light emitted by the first light source emitting end 51 after passing through the first fixed grating 70 and the movable grating 90. The second photoelectric sensor 60 has a second light source emitting end 61 and a second light source receiving end 62 for receiving light emitted by the second light source emitting end 61 after passing through the second fixed grating 80 and the movable grating 90. The VCM motor 40, the first light source receiving end 52, and the second light source receiving end 62 are all connected to the main controller. In this invention, the main controller is an MCU, and the first light source receiving end 52 and the second light source receiving end 62 are both photosensitive components. The light emitted by the first light source emitting end 51 and the second light source emitting end 61 have the same light intensity and do not interfere with each other. The light signal intensity received by the first light source receiving end 52 and the light signal intensity received by the second light source receiving end 62 are 90 degrees out of phase.

[0047] The first photoelectric sensor 50, the second photoelectric sensor 60, the first fixed grating 70, and the second fixed grating 80 are all fixedly mounted on the mounting base 10, and the first fixed grating 70 and the second fixed grating 80 are sequentially arranged on the same side of the movable grating 90 along the rotation direction of the movable turntable 20. In this invention, the first fixed grating 70, the second fixed grating 80, the movable grating 90, and the VCM motor 40 are all designed in an arc shape, and the rotation axes of the first fixed grating 70, the second fixed grating 80, and the movable grating 90 all coincide with the rotation axis of the movable turntable 20. In this embodiment, for ease of installation and use, the first fixed grating 70 and the second fixed grating 80 are integrally connected, that is, the first fixed grating 70 and the second fixed grating 80 are a single structure. It should be understood that in actual use, the first fixed grating 70 and the second fixed grating 80 can also be arranged separately. Specifically, the first fixed grating 70 and the second fixed grating 80 are provided with a first fixed through hole. During assembly, screws pass through the first fixed through hole and engage with the screw holes on the fixed turntable to fix the first fixed grating 70 and the second fixed grating 80 on the fixed turntable. The movable grating 90 is provided with a second fixed through hole. During assembly, screws pass through the second fixed through hole and engage with the screw holes on the movable turntable 20 to fix the movable grating 90 on the movable turntable 20.

[0048] The first fixed grating 70 has multiple identical first light-transmitting slots 71 arranged in an arc shape, the second fixed grating 80 has multiple identical second light-transmitting slots 81 arranged in an arc shape, and the movable grating 90 has multiple identical third light-transmitting slots 91 arranged in an arc shape. The spacing between the first light-transmitting slots 71, second light-transmitting slots 81, and third light-transmitting slots 91 is the same. The number of first light-transmitting slots 71 and second light-transmitting slots 81 is the same, and the number of third light-transmitting slots 91 is greater than the number of first light-transmitting slots 71 and second light-transmitting slots 81. The curvature of the first light-transmitting slots 71, second light-transmitting slots 81, and third light-transmitting slots 91 is the same. The arc corresponding to the width of the first light-transmitting groove 71, the second light-transmitting groove 81, and the third light-transmitting groove 91 is 0.18 to 0.22°, preferably 0.2°; the spacing between the first light-transmitting groove 71, the second light-transmitting groove 81, and the third light-transmitting groove 91 is 0.18 to 0.22°, preferably 0.2°; the distance between the first fixed grating 70, the second fixed grating 80, and the movable grating 90 is 0.1 to 0.2 mm, preferably 0.15 mm; the thickness of the first fixed grating 70, the second fixed grating 80, and the movable grating 90 is 0.15 to 0.20 mm, preferably 0.175 mm.

[0049] like Figure 5 As shown, in this embodiment, the VCM motor 40 includes a motor bracket 41, a first magnet 43, a second magnet 44, and a coil 42. The first magnet 43 and the second magnet 44 are arranged parallel to each other on the motor bracket 41, with a distance of 2.3 mm between them. The coil 42 is located between the first magnet 43 and the second magnet 44. The magnetic poles of adjacent sides of the first magnet 43 and the second magnet 44 are opposite. A first magnetic field and a second magnetic field with opposite directions are formed between the first magnet 43 and the second magnet 44 on both sides of the magnetic pole boundary line. The coil 42 has two short sides located in the first magnetic field and the second magnetic field, respectively. The currents passing through the two short sides are in opposite directions and are perpendicular to the magnetic field direction of their respective magnetic fields. The movable turntable 20 is provided with spaced locking blocks 21, and the coil 42 is fixedly wound around the outside of the locking blocks 21.

[0050] Specifically, in this embodiment, the magnetic poles on the left and right sides of the first magnet 43 are N and S poles, respectively, while the magnetic poles on the left and right sides of the second magnet 44 are S and N poles, respectively. Since the magnitude of the Ampere force on the bent wire in the magnetic field is equivalent to the Ampere force on the straight wire from the starting point to the ending point, when a current is passed through the coil 42 in the direction indicated by the arrow, according to Fleming's left-hand rule, the Ampere force on the coil 42 is the superposition of the Ampere forces on the two long sides and the two short sides, causing the coil 42 to move from left to right and cut the magnetic field lines perpendicularly. The coil 42 will then drive the movable turntable 20 to rotate to the right. When the opposite current is passed through, the coil 42 will drive the movable turntable 20 to rotate to the left. Since the Ampere force F on the conductor is equal to the product of the magnetic induction intensity B, the current I, and the effective length L of the conductor, the formula is F = BILsina, where α is the angle between the current direction and the magnetic field direction. Therefore, in practical work, the magnitude and direction of the Ampere force can be controlled by controlling the magnitude and direction of the current I through the MCU, thereby controlling the rotation direction and speed of the movable turntable 20. It should be understood that the positions of the long side or the short side in this application can be interchanged in actual use, that is, the two long sides can be located in two different magnetic fields.

[0051] like Figure 6 As shown, in this invention, the VCM motor can also adopt a structure with only the first magnet 43. In this case, the coil 42 is located on one side of the first magnet 43, and the plane of the coil 42 is parallel to the side surface of the first magnet 43. The first magnet 43 forms two magnetic field regions with different magnetic field directions on both sides of the magnetic pole dividing line. The coil 42 has coil segments located in the two magnetic field regions, i.e., two short sides. It should be understood that the number and arrangement of magnets can also be set according to actual needs, and are not limited to a single magnet; multiple spliced ​​magnets can also be used.

[0052] The closed-loop control process of this invention is as follows:

[0053] (1) Make the first light source emitting end 51 and the second light source emitting end 61 emit light of constant intensity. The VCM motor 40 controls the rotating turntable 20 to rotate. The movable grating 90 moves with the rotating turntable 20. The first light source receiving end 52 receives the light from the first light source passing through the first fixed grating 70 and the movable grating 90. The second light source receiving end 62 receives the light from the second light source passing through the second fixed grating 80 and the movable grating 90.

[0054] (2) The main controller converts the light intensity signals of the light received by the first light source receiver 52 and the second light source receiver 62 into periodically changing electrical signals y1(x) and y2(x), respectively, with the phase difference between the electrical signals y1(x) and y2(x) being 90 degrees.

[0055] (3) The main controller divides the electrical signals y1(x) and y2(x) within a single cycle into four parts. If y1(x) is less than or equal to 0 and y2(x) is less than 0, this is recorded as the first part. If y1(x) is less than or equal to 0 and y2(x) is greater than or equal to 0, this is recorded as the second part. If y1(x) is greater than 0 and y2(x) is greater than or equal to 0, this is recorded as the third part. If y1(x) is greater than 0 and y2(x) is less than 0, this is recorded as the fourth part. Then, different operations are performed on each part:

[0056] Part 1: y = ((2*y2(x)min-y2(x)+y1(x))+y2(x)min);

[0057] Part Two: y = (y2(x) + y1(x) + y2(x)min);

[0058] Part 3: y = ((2*y1(x)max-y1(x)+y2(x))+y2(x)min);

[0059] Part 4: y = ((2*y1(x)max - y1(x) - y2(x)) + y2(x)min);

[0060] Here, y2(x)min refers to the minimum value of y2(x), which is equal to y1(x)min, and y1(x)max refers to the maximum value of y1(x), which is equal to y2(x)max. Combining these four parts yields the offset value y of y1(x) and y2(x) that changes periodically as the movable grating 90 moves, and the offset value y within the same period is directly proportional to the rotation angle of the movable grating 90.

[0061] (4) The angle of rotation of the active grating 90 relative to the origin is calculated according to the formula A=nθ+ykθ, where n is the number of cycles of the offset value y, θ is the angle of rotation of the active grating 90 corresponding to one cycle of the offset value y, y is the offset value in the current cycle calculated in step (3), and k is the proportional coefficient between the offset value y and θ.

[0062] (5) The main controller controls the VCM motor 40 to work according to the angle calculated in step (4).

[0063] like Figure 8 As shown, in this invention, the electrical signals y1(x) and y2(x) both have offset values ​​y that change with the same period. Specifically, y1(x) and y2(x) are triangular wave voltage signals with a phase difference of 90 degrees.

[0064] To facilitate the determination of the rotation direction of the movable turntable 20, the offset values ​​within the same cycle calculated in step (3) are divided into several segments, sorted by numbers, and marked. The rotation direction of the movable turntable 20 can then be determined based on the order of the numbers. For example... Figure 9 As shown, in this embodiment, the offset value within the same period is divided into three segments and marked with 1, 2, and 3 in sequence. During the detection process, as the movable turntable 20 rotates, the offset value will change from 1, 2, 3 or 3, 2, 1, thereby determining whether the movable turntable 20 is moving away from or closer to the origin.

[0065] In summary, the VCM motor and grating used in this invention can be configured in an arc shape according to the aperture structure, occupying little space and perfectly matching the aperture design structure. Angle detection can be achieved by using two light sources, resulting in low energy consumption and minimal space requirements. By converting the two optical signals into electrical signals, and then using the atan2 function concept to convert the electrical signals of the two light sources into an offset value proportional to the angle, the actual rotation angle can be obtained quickly and accurately. The main controller then controls the VCM motor based on the calculated rotation angle, achieving closed-loop control of the aperture movement, improving control accuracy, enabling automatic correction, and enhancing resistance to external interference. Furthermore, the VCM motor responds faster than a stepper motor, ensuring rapid acquisition of the desired aperture size and improving aperture performance.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the actual technology of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An aperture motion closed loop control system comprising a fixed base, a movable turntable, a blade moved by the movable turntable, a blade guide for guiding the movement of the blade to form different aperture sizes, characterized in that, Also include a VCM motor for controlling the rotation of the active turntable relative to the fixed seat and a detection mechanism for detecting the rotation angle of the active turntable, the detection mechanism includes a first fixed grating, a second fixed grating, an active grating, a first photoelectric sensor, a second photoelectric sensor and a main controller, the active grating is fixed on the active turntable, the first photoelectric sensor has a first light source emitting end and a first light source receiving end for receiving the light line of the first light source emitting end after passing through the first fixed grating and the active grating, the second photoelectric sensor has a second light source emitting end and a second light source receiving end for receiving the light line of the second light source emitting end after passing through the second fixed grating and the active grating, the VCM motor, the first light source receiving end and the second light source receiving end are connected with the main controller; The closed loop control process is as follows: (1) make the first light source emitting end and the second light source emitting end emit light with constant intensity, the VCM motor controls the rotation of the active turntable, the active grating moves with the active turntable, the first light source receiving end receives the light line of the first light source through the first fixed grating and the active grating, and the second light source receiving end receives the light line of the second light source through the second fixed grating and the active grating; (2) the main controller converts the light intensity signals of the light lines received by the first light source receiving end and the second light source receiving end into periodic variation electric signals y1(x) and y2(x) respectively, and the phases of the electric signals y1(x) and y2(x) are 90 degrees; (3) the main controller divides the electric signals y1(x) and y2(x) in a single period into four parts, if y1(x) is less than or equal to 0 and y2(x) is less than 0, it is recorded as the first part, if y1(x) is less than or equal to 0 and y2(x) is greater than or equal to 0, it is recorded as the second part, if y1(x) is greater than 0 and y2(x) is greater than or equal to 0, it is recorded as the third part, if y1(x) is greater than 0 and y2(x) is less than 0, it is recorded as the fourth part, then different operations are carried out on each part: First part: y = ((2*y2(x)min-y2(x)+y1(x))+y2(x)min); Second part: y = (y2(x)+y1(x)+y2(x)min); Third part: y = ((2*y1(x)max-y1(x)+y2(x))+y2(x)min); Fourth part: y = ((2*y1(x)max-y1(x)-y2(x))+y2(x)min); Here y2(x)min refers to the minimum value of y2(x), which is equal to y1(x)min, y1(x)max refers to the maximum value of y1(x), which is equal to y2(x)max, the four parts are combined to obtain the offset value y about the periodic variation of y1(x) and y2(x) with the movement of the active grating, and the offset value y in the same period is proportional to the rotation angle value of the active grating. (4) The angle of rotation of the active grating relative to the origin is calculated according to the formula A=nθ+ykθ, where n is the number of cycles of the offset value y, θ is the angle of rotation of the active grating corresponding to one cycle of the offset value y, y is the offset value in the current cycle calculated in step (3), and k is the proportional coefficient between the offset value y and θ. (5) The main controller controls the VCM motor to work based on the angle calculated in step (4).

2. The aperture motion closed loop control system of claim 1, wherein, The first photoelectric sensor, the second photoelectric sensor, the first fixed grating, and the second fixed grating are all fixedly mounted on the fixed base, and the first fixed grating and the second fixed grating are sequentially arranged on the same side of the movable grating along the rotation direction of the movable turntable.

3. The aperture motion closed loop control system of claim 2, wherein, The first fixed grating and the second fixed grating are at the same distance from the movable grating, and the first fixed grating and the second fixed grating are integrally connected.

4. The aperture motion closed loop control system of claim 1, wherein, The first fixed grating has a plurality of identical first light-transmitting slots arranged in an arc shape, the second fixed grating has a plurality of identical second light-transmitting slots arranged in an arc shape, and the movable grating has a plurality of identical third light-transmitting slots arranged in an arc shape. The spacing between the first light-transmitting slots, the second light-transmitting slots, and the third light-transmitting slots is the same.

5. The aperture motion closed loop control system of claim 4, wherein, The number of the first and second light-transmitting slots is the same, and the number of the third light-transmitting slots is greater than the number of the first and second light-transmitting slots. The width of the first, second, and third light-transmitting slots is the same.

6. The aperture motion closed loop control system of claim 1, wherein, The VCM motor includes a motor bracket, a coil, and a magnet that generates an Ampere force in the coil when the coil is energized. The magnet is located on both sides of the magnetic pole dividing line, forming two magnetic field regions with different magnetic field directions. The coil has coil segments located in the two magnetic field regions respectively.

7. The aperture motion closed loop control system of claim 6, wherein, The movable turntable is equipped with spaced-out locking blocks, and the coil is fixedly wound around the outside of the locking blocks.

8. The aperture motion closed loop control system of claim 1, wherein, The intensity of the light signal received by the first light source receiver is 90 degrees out of phase with the intensity of the light signal received by the second light source receiver.

9. The aperture motion closed loop control system of claim 1, wherein, The light emitted by the first light source and the second light source has the same intensity and does not interfere with each other.

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