Angle measurement system and precision control method thereof

Abstract

The angle measuring system comprises a final gear, a driving unit, a forward rotation double gear set, a reverse rotation double gear set, a solid shaft, a hollow shaft, a first encoder, a second encoder and a shell, wherein the final gear is used to be connected with a load; the driving unit is connected with the final gear to drive the final gear to rotate; the forward rotation double gear set is installed at one end of the solid shaft; the end of the solid shaft away from the forward rotation double gear set is located in the hollow shaft and is rotatably assembled with the hollow shaft; the reverse rotation double gear set is coaxially arranged on one side of the forward rotation double gear set; the end of the hollow shaft away from the reverse rotation double gear set is located in the shell and is rotatably assembled with the shell; the first encoder is installed in the shell and is connected with the solid shaft; and the second encoder is installed in the shell and is connected with the hollow shaft. The angle measuring system can effectively solve the problem of high-precision measurement during forward and reverse rotation, and can perform error compensation on the angle and complete high-precision angle measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of angle measurement systems, and in particular to an angle measurement system and a precision control method thereof. Background Art

[0002] Coaxially mounted turntable angle measurement systems are often limited by the turntable's internal dimensions and layout. While clockwise rotation generally maintains angular accuracy, counterclockwise reversal can easily cause angle measurement offsets. Consequently, existing angle measurement devices are generally suitable for continuous, single-direction rotation or low reversal acceleration, and cannot meet the requirements for high-precision angle measurement. Summary of the Invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes an angle measurement system and an accuracy control method thereof.

[0004] The present invention proposes an angle measurement system comprising: a final gear, a drive unit, a clockwise double-piece gear set, a counterclockwise double-piece gear set, a solid shaft, a hollow shaft, a first encoder, a second encoder, and a housing, wherein:

[0005] The final gear is used to connect with the load; the driving unit is connected to the final gear to drive the final gear to rotate;

[0006] A clockwise double-piece gear set is mounted on one end of a solid shaft, comprising a first lower gear and a first upper gear coaxially arranged, and a first tension spring arranged along the rotation direction of the first lower gear and the first upper gear and connected at both ends to the first lower gear and the first upper gear, wherein the first lower gear is fixedly assembled with the solid shaft, and the first upper gear is rotatably mounted on the first lower gear, the first lower gear and the first upper gear are respectively engaged with the final gear, and the first tension spring is in a stressed state;

[0007] One end of the solid shaft away from the clockwise double-piece gear set is located in the hollow shaft and is rotatably assembled with the hollow shaft, and the solid shaft and the hollow shaft are coaxial;

[0008] The reverse double-piece gear set is coaxially arranged on one side of the forward double-piece gear set and is installed at one end of the hollow shaft. It includes a second lower piece gear and a second upper piece gear that are coaxially arranged, and a second tension spring that is arranged along the rotation direction of the second lower piece gear and the second upper piece gear and whose two ends are respectively connected to the second lower piece gear and the second upper piece gear, and the second lower piece gear is fixedly assembled with the solid shaft, and the second upper piece gear is rotatably installed on the second lower piece gear, and the second lower piece gear and the second upper piece gear are respectively engaged with the final gear, and the second tension spring is in a stressed state;

[0009] One end of the hollow shaft away from the reverse double-piece gear set is located in the housing and is rotatably assembled with the housing;

[0010] The first encoder is installed in the housing and connected to the solid shaft; the second encoder is installed in the housing and connected to the hollow shaft.

[0011] Preferably, the first upper gear is provided with a first upper arc hole arranged along its circumference, and the first lower gear is located below the first upper arc hole and is provided with a first lower arc hole coaxially arranged with the first upper arc hole; one end of the first tension spring is located in the first upper arc hole and connected to the first upper gear, and the other end thereof is located in the first lower arc hole and connected to the first lower gear.

[0012] Preferably, the first upper gear is provided with a first upper hole at one end of its first upper arc hole; the first lower gear is provided with a first lower hole at the other end of its first lower arc hole away from the end where the first upper hole is located, and the two ends of the first tension spring are respectively hooked in the first upper hole and the first lower hole.

[0013] Preferably, the second upper gear is provided with a second upper arc hole arranged along its circumference, and the second lower gear is located below the second upper arc hole and is provided with a second lower arc hole coaxially arranged with the second upper arc hole; one end of the second tension spring is located in the second upper arc hole and connected to the second upper gear, and the other end thereof is located in the second lower arc hole and connected to the second lower gear.

[0014] Preferably, the second upper gear is provided with a second upper hole at one end of its second upper arc hole; the second lower gear is provided with a second lower hole at the other end of its second lower arc hole away from the end where the second upper hole is located, and the two ends of the second tension spring are respectively hooked in the second upper hole and the second lower hole.

[0015] Preferably, the solid shaft and the hollow shaft are rotatably assembled via a first bearing; and the hollow shaft and the housing are rotatably assembled via a second bearing.

[0016] Preferably, the first encoder is connected to the end of the solid shaft away from the clockwise double-piece gear set through a coupling.

[0017] Preferably, the second encoder is a hollow encoder, and one end of the hollow shaft away from the reverse double-piece gear set extends into the second encoder to form a connection between the second encoder and the hollow shaft.

[0018] Preferably, the first encoder and the second encoder are both installed in the housing via a transition bracket.

[0019] The present invention proposes a method for controlling the accuracy of an angle measurement system, comprising the following steps:

[0020] A target is pre-set on the final gear and a laser tracker is provided for measuring the target's coordinate position;

[0021] The initial state is that the coordinates of the target measured by the laser tracker is P1=(X1, Y1), and the readings of the first encoder and the second encoder are both 0 at this time;

[0022] When the final gear is rotated clockwise or counterclockwise, the coordinates of the target P i =(X i ,Y i ) are measured in a range of one rotation, and the readings of the first encoder θ i are recorded when the final gear is rotated clockwise, and the readings of the second encoder ψ i are recorded when the final gear is rotated counterclockwise, where i is a discrete point passed by the target in a range of one rotation of the final gear;

[0023] A standard circle is fitted according to the coordinates of the multiple points P =(X

[0024] ,Y ), and the center O(X0, Y0) of the circle is obtained when the target rotates one circle, so that the theoretical measurement angle when rotated clockwise or counterclockwise satisfies:

[0025] The collection error value between the readings of the first encoder and the theoretical measurement angle when the final gear is rotated clockwise is Δ i = θ i - α i , and a continuous function Δ1 is fitted according to the discrete error values;

[0026] The collection error value between the readings of the second encoder and the theoretical measurement angle when the final gear is rotated counterclockwise is Δ i = ψ i - α i , and a continuous function Δ2 is fitted according to the discrete error values;

[0027] When the final gear is rotated clockwise, the readings of the first encoder after error compensation correction are θ+Δ1, and the angle of the continuously rotated final gear is completed by the modified value θ+Δ1 of the readings of the first encoder for error compensation;

[0028] When the final gear is rotated counterclockwise, the readings of the second encoder after error compensation correction are ψ+Δ2, and the angle of the continuously rotated final gear is completed by the modified value ψ+Δ2 of the readings of the second encoder for error compensation.

[0029] In the present invention, the final gear is connected to the load and is provided with rotational power by a drive unit (not shown); the clockwise double-piece gear set and the counter-clockwise double-piece gear set are fitted with the final gear to complete the transmission of rotational motion; the clockwise double-piece gear set is connected to the first encoder via a solid shaft, and the counter-clockwise double-piece gear set is connected to the second encoder via a hollow shaft, and the rotational motions of the solid shaft and the hollow shaft are independent of each other. The clockwise double-piece gear set includes two first lower gears and a first upper gear with the same module and the same number of teeth. The first lower gear is fixed to the solid shaft, and the first upper gear can rotate around the first lower gear. When the clockwise double-piece gear set is engaged with the final gear, the first lower gear and the first upper gear are staggered by 2-3 teeth and are fixed to the corresponding teeth of the final gear by a first tension spring, so as to eliminate the meshing clearance between the clockwise double gear and the final gear by the first tension spring. The counter-rotating double-gear set consists of two lower gears with the same module and number of teeth, and a second upper gear. The second lower gear is fixed to a hollow shaft, while the second upper gear rotates around it. When the counter-rotating double-gear set meshes with the final gear, the second lower gear and the second upper gear are offset by two to three teeth. A second tension spring secures them to corresponding teeth on the final gear, eliminating meshing backlash between the two gears. When the final gear rotates clockwise, the angle of the final gear is read by a first encoder. When the final gear rotates counterclockwise, the angle of the final gear is read by a second encoder. This system, with two sets of double-gear sets meshing with the final gear and rotating independently of each other, and each connected to two encoders, effectively solves the problem of high-precision measurement during forward and reverse motion. Furthermore, combined with appropriate measuring instruments, angle error compensation is performed to achieve high-precision angle measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural schematic diagram of an angle measurement system proposed by the present invention;

[0031] Figure 2 This is a structural schematic diagram of the clockwise double-piece gear set in the angle measurement system proposed by the present invention;

[0032] Figure 3 This is a structural schematic diagram of the reverse double-piece gear set in the angle measurement system proposed by the present invention;

[0033] Figure 4 This is a structural schematic diagram of the housing in an angle measurement system proposed by the present invention;

[0034] Figure 5 This is an enlarged view of the meshing surface between the clockwise-rotating double-piece gear set and the final-stage gear when the final-stage gear in the angle measurement system proposed by the present invention rotates clockwise;

[0035] Figure 6This is an enlarged view of the meshing surface between the reverse double-piece gear set and the final gear when the final gear in the angle measurement system proposed by the present invention rotates counterclockwise;

[0036] Figure 7 This is the angle error compensation measurement diagram described in the accuracy control method of the angle measurement system proposed by the present invention. DETAILED DESCRIPTION

[0037] Reference Figure 1-4 The present invention proposes an angle measurement system comprising: a final gear 01, a drive unit, a clockwise double-piece gear set 02, a counterclockwise double-piece gear set 03, a solid shaft 04, a hollow shaft 05, a first encoder 09, a second encoder 10, and a housing 06. The final gear 01 is configured to connect to a load. The drive unit is connected to the final gear 01 to drive the final gear 01 to rotate.

[0038] The clockwise double-piece gear set 02 is installed at one end of the solid shaft 04, and includes a first lower gear 02A and a first upper gear 02B arranged coaxially, and a first tension spring 02C arranged along the rotation direction of the first lower gear 02A and the first upper gear 02B and connected to the first lower gear 02A and the first upper gear 02B at both ends, and the first lower gear 02A is fixedly assembled with the solid shaft 04, and the first upper gear 02B is rotatably installed on the first lower gear 02A so that the first upper gear 02B can rotate around the first lower gear 02A.

[0039] The first lower gear 02A and the first upper gear 02B are respectively engaged with the final gear 01, and the first tension spring 02C is in a stressed state, that is, when the clockwise double-piece gear set 02 is engaged with the final gear 01, the first lower gear 02A and the first upper gear 02B are staggered by several teeth, generally 2-3 teeth, and are respectively engaged with the corresponding teeth of the final gear 01 under the force of the first tension spring 02C.

[0040] The end of the solid shaft 04 away from the clockwise double-piece gear set 02 is located in the hollow shaft 05 and is rotatably assembled with the hollow shaft 05. The solid shaft 04 and the hollow shaft 05 are coaxial so that the solid shaft 04 and the hollow shaft 05 can rotate relative to each other, thereby making the rotational motion of the two relatively independent.

[0041] The reverse double-piece gear set 03 is coaxially arranged on one side of the forward double-piece gear set 02 and installed at one end of the hollow shaft 05. It includes a coaxially arranged second lower gear 03A and a second upper gear 03B, and a second tension spring 03C arranged along the rotation direction of the second lower gear 03A and the second upper gear 03B and connected to the second lower gear 03A and the second upper gear 03B at both ends. The second lower gear 03A is fixedly assembled with the solid shaft 04, and the second upper gear 03B is rotatably installed on the second lower gear 03A so that the second upper gear 03B can rotate around the second lower gear 03A.

[0042] The second lower gear 03A and the second upper gear 03B are respectively engaged with the final gear 01, and the second tension spring 03C is in a stressed state, that is, when the reverse double-piece gear set 03 is engaged with the final gear 01, the second lower gear 03A and the second upper gear 03B are staggered by several teeth, generally 2-3 teeth, and are respectively engaged with the corresponding teeth of the final gear 01 under the force of the second tension spring 03C.

[0043] One end of the hollow shaft 05 away from the reverse double-plate gear set 03 is located in the housing 06 and is rotatably assembled with the housing 06 so that the hollow shaft 05 can rotate relative to the housing 06.

[0044] The first encoder 09 is installed in the housing 06 and connected to the solid shaft 04 , and the second encoder 10 is installed in the housing 06 and connected to the hollow shaft 05 .

[0045] Reference Figure 5-6 During operation, when final gear 01 rotates clockwise, the first lower gear 02A in the clockwise double-piece gear set 02 meshes with the tooth surface 011 on one side of final gear 01. At this time, the angle value of final gear 01 is read by the first encoder 09. When final gear 01 rotates counterclockwise, the second lower gear 03A in the counterclockwise double-piece gear set 03 meshes with the tooth surface 012 on the other side of final gear 01. At this time, the angle value of final gear 01 is read by the second encoder 10. This structural design effectively solves the problem of high-precision measurement during forward and reverse rotation.

[0046] Furthermore, in this embodiment, the first upper gear 02B is provided with a first upper arcuate hole arranged along its circumference, and the first lower gear 02A is provided with a first lower arcuate hole coaxially arranged with the first upper arcuate hole, located below the first upper arcuate hole. One end of a first tension spring 02C is located within the first upper arcuate hole and connected to the first upper gear 02B, while the other end is located within the first lower arcuate hole and connected to the first lower gear 02A. When the first upper gear 02B rotates relative to the first lower gear 02A, its rotation angle is constrained by the first tension spring 02C. Subsequently, when meshing with the final gear 01, the first lower gear 02A and the first upper gear 02B are forced by the first tension spring 02C to engage with corresponding teeth of the final gear 01.

[0047] Furthermore, first upper gear 02B has a first upper hole at one end of its first upper arc-shaped hole; first lower gear 02A has a first lower hole at the other end of its first lower arc-shaped hole, away from the first upper hole. The two ends of first tension spring 02C are hooked into the first upper hole and first lower hole, respectively. This connects first tension spring 02C to first upper gear 02B and first lower gear 02A, making this structural design easy to disassemble and replace.

[0048] Similarly, the second upper gear 03B is provided with a second upper arc-shaped hole arranged along its circumference, and the second lower gear 03A is provided with a second lower arc-shaped hole arranged coaxially with the second upper arc-shaped hole below the second upper arc-shaped hole. One end of the second tension spring 03C03C is located in the second upper arc-shaped hole and connected to the second upper gear 03B, and the other end is located in the second lower arc-shaped hole and connected to the second lower gear 03A. When the second upper gear 03B rotates relative to the second lower gear 03A, its rotation angle is constrained by the second tension spring 03C. Subsequently, when meshing with the final gear 01, the second lower gear 03A and the second upper gear 03B can be forced to mesh with the corresponding teeth of the final gear 01 through the second tension spring 03C.

[0049] Furthermore, the second upper gear 03B has a second upper hole at one end of its second upper arc-shaped hole; the second lower gear 03A has a second lower hole at the other end of its second lower arc-shaped hole, away from the second upper hole. The two ends of the second tension spring 03C are hooked into the second upper hole and the second lower hole, respectively. This connects the second tension spring 03C to the second upper gear 03B and the second lower gear 03A, making this structural design easy to disassemble and replace.

[0050] In this embodiment, the solid shaft 04 and the hollow shaft 05 are rotatably assembled via two sets of first bearings 13 , and the hollow shaft 05 and the housing 06 are rotatably assembled via two sets of second bearings 14 .

[0051] In this embodiment, both the first encoder 09 and the second encoder 10 are mounted within the housing 06 via a transition bracket 7. The first encoder 09 is connected to the end of the solid shaft 04 away from the clockwise double-piece gear set 02 via a coupling 8. The second encoder 10 is a hollow encoder, with the end of the hollow shaft 05 away from the counter-rotating double-piece gear set 03 extending into the second encoder 10 to form a connection between the second encoder 10 and the hollow shaft 05.

[0052] Reference Figure 7 The present invention proposes a precision control method for an angle measurement system, comprising the following steps:

[0053] A target 11 is pre-set on the final gear 01 so that the target 11 rotates as the final gear 1 rotates; a laser tracker 12 is also provided for measuring the coordinate position of the target 11;

[0054] In the initial state, the coordinates of the target measured by the laser tracker 12 are P1 = (X1, Y1), and the readings θ of the first encoder 09 and ψ of the second encoder 10 are calibrated to be 0.

[0055] When the final gear 01 is rotated clockwise, the target coordinate P is measured within one rotation. i =(X i ,Y i ), and record the reading θ of the first encoder 09 i , where i is the discrete point that the target passes through within one rotation of the final gear 01;

[0056] According to the coordinates of multiple points Pi = (Xi, Yi) fitting a standard circle, the center of the target's rotation is obtained as O (X0, Y0). Then the theoretical measurement angle of clockwise rotation satisfies:

[0057]

[0058] The acquisition error between the reading of the first encoder 09 and the theoretical measurement angle is: Δ i =θ i -α i , and fit the continuous function Δ1 according to the discrete error value;

[0059] When the final gear 01 rotates clockwise, the reading of the first encoder 09 after error compensation is θ+Δ1. The angle of the final gear 01 that rotates continuously clockwise completes the error compensation through the correction value θ+Δ1 of the reading of the first encoder 09.

[0060] When the final gear 01 is rotated counterclockwise, the target coordinate P is measured within one rotation. i =(X i ,Y i), and record the reading ψ of the second encoder 10 i where i is the discrete point passed by the target within the range of one rotation of the final gear 01;

[0061] According to the coordinates of the plurality of points Pi=(Xi, Yi), a standard circle is fitted, the center of the circle O(X0, Y0) is obtained when the target rotates one round, and the theoretically measured angle of counterclockwise rotation satisfies:

[0062]

[0063] The collection error value of the reading of the second encoder 10 and the theoretically measured angle is Δ i = ψ i - α i , and a continuous function Δ2 is fitted according to the discrete error values;

[0064] When the final gear 01 rotates counterclockwise, the reading of the second encoder 10 after error compensation correction is ψ+Δ2, and the angle of the continuously rotating final gear 01 is completed by the error compensation of the reading of the second encoder 10.

[0065] As can be seen from the above, in the present invention, the final gear 01 is connected to the load and is provided with rotational power by a drive unit (not shown); the clockwise double-piece gear set 02 and the counter-clockwise double-piece gear set 03 are fitted with the final gear 01 to complete the transmission of rotational motion; the clockwise double-piece gear set 02 is connected to the first encoder 09 via a solid shaft 04, and the counter-clockwise double-piece gear set 03 is connected to the second encoder 10 via a hollow shaft 05. The rotational motions of the solid shaft 04 and the hollow shaft 05 are independent of each other. The clockwise double-piece gear set 02 includes two first lower gears 02A and a first upper gear 02B with the same module and number of teeth. The first lower gear 02A is fixed to the solid shaft 04, and the first upper gear 02B can rotate around the first lower gear 02A. When the clockwise double-piece gear set 02 is engaged with the final gear 01, the first lower gear 02A and the first upper gear 02B are staggered by 2-3 teeth and are fixed to the corresponding teeth of the final gear 01 by a first tension spring 02C. The counter-rotating double-gear set 03 consists of two lower gears 03A and a second upper gear 03B with the same module and number of teeth. The second lower gear 03A is fixed to a hollow shaft 05, while the second upper gear 03B rotates around it. When the counter-rotating double-gear set 03 engages the final gear 01, the second lower gear 03A and the second upper gear 03B are offset by two to three teeth and secured to corresponding teeth on the final gear 01 by a second tension spring 03C. When the final gear 01 rotates clockwise, the angle of the final gear 01 is read by the first encoder 09. When the final gear 01 rotates counterclockwise, the angle of the final gear 01 is read by the second encoder 10. This system, with two sets of double-gear sets meshing with the final gear 01 and rotating independently of each other, and each connected to two sets of encoders, effectively solves the problem of high-precision measurement during forward and reverse motion. Furthermore, when combined with appropriate measuring instruments, angle error compensation is achieved, enabling high-precision angle measurement.

[0066] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An angle measurement system, characterized in that: include: A final gear (01), a drive unit, a clockwise double-piece gear set (02), a counterclockwise double-piece gear set (03), a solid shaft (04), a hollow shaft (05), a first encoder (09), a second encoder (10), and a housing (06), wherein: The final gear (01) is used to be connected to a load; the driving unit is connected to the final gear (01) to drive the final gear (01) to rotate; The clockwise double-piece gear set (02) is installed on one end of the solid shaft (04), and comprises a first lower piece gear (02A) and a first upper piece gear (02B) arranged coaxially, and a first tension spring (02C) arranged along the rotation direction of the first lower piece gear (02A) and the first upper piece gear (02B) and connected to the first lower piece gear (02A) and the first upper piece gear (02B) at both ends, and the first lower piece gear (02A) is fixedly assembled with the solid shaft (04), and the first upper piece gear (02B) is rotatably installed on the first lower piece gear (02A), and the first lower piece gear (02A) and the first upper piece gear (02B) are respectively engaged with the final gear (01), and the first tension spring (02C) is in a stressed state; One end of the solid shaft (04) away from the clockwise double-piece gear set (02) is located in the hollow shaft (05) and is rotatably assembled with the hollow shaft (05), and the solid shaft (04) and the hollow shaft (05) are coaxial; The reverse double-piece gear set (03) is coaxially arranged on one side of the forward double-piece gear set (02) and installed on one end of the hollow shaft (05), and comprises a second lower piece gear (03A) and a second upper piece gear (03B) which are coaxially arranged, and a second tension spring (03C) which is arranged along the rotation direction of the second lower piece gear (03A) and the second upper piece gear (03B) and whose two ends are respectively connected to the second lower piece gear (03A) and the second upper piece gear (03B), and the second lower piece gear (03A) is fixedly assembled with the solid shaft (04), and the second upper piece gear (03B) is rotatably installed on the second lower piece gear (03A), and the second lower piece gear (03A) and the second upper piece gear (03B) are respectively engaged with the final gear (01), and the second tension spring (03C) is in a stressed state; One end of the hollow shaft (05) away from the reverse double-piece gear set (03) is located in the housing (06) and is rotatably assembled with the housing (06); The first encoder (09) is installed in the housing (06) and connected to the solid shaft (04); the second encoder (10) is installed in the housing (06) and connected to the hollow shaft (05).

2. The angle measurement system according to claim 1, characterized in that The first upper gear (02B) is provided with a first upper arc hole arranged along its circumference, and the first lower gear (02A) is provided with a first lower arc hole arranged coaxially with the first upper arc hole at a position below the first upper arc hole; one end of the first tension spring (02C) is located in the first upper arc hole and is connected to the first upper gear (02B), and the other end is located in the first lower arc hole and is connected to the first lower gear (02A).

3. The angle measurement system according to claim 2, characterized in that: The first upper gear (02B) is provided with a first upper hole at one end of its first upper arc hole; the first lower gear (02A) is provided with a first lower hole at the other end of its first lower arc hole away from the end where the first upper hole is located, and the two ends of the first tension spring (02C) are hooked in the first upper hole and the first lower hole respectively.

4. The angle measurement system according to claim 1, characterized in that The second upper gear (03B) is provided with a second upper arc hole arranged along its circumference, and the second lower gear (03A) is provided with a second lower arc hole coaxially arranged with the second upper arc hole at a position below the second upper arc hole; one end of the second tension spring (03C) (03C) is located in the second upper arc hole and connected to the second upper gear (03B), and the other end is located in the second lower arc hole and connected to the second lower gear (03A).

5. The angle measurement system according to claim 4, characterized in that: The second upper gear (03B) is provided with a second upper hole at one end of its second upper arc hole; the second lower gear (03A) is provided with a second lower hole at the other end of its second lower arc hole away from the end where the second upper hole is located, and the two ends of the second tension spring (03C) are respectively hooked in the second upper hole and the second lower hole.

6. The angle measurement system according to claim 1, characterized in that: The solid shaft (04) and the hollow shaft (05) are rotatably assembled via a first bearing (13); the hollow shaft (05) and the housing (06) are rotatably assembled via a second bearing (14).

7. The angle measurement system according to claim 1, characterized in that: The first encoder (09) is connected to one end of the solid shaft (04) away from the clockwise double-piece gear set (02) through a coupling (8).

8. The angle measurement system according to claim 1, characterized in that: The second encoder (10) is a hollow encoder, and one end of the hollow shaft (05) away from the reverse double-piece gear set (03) extends into the second encoder (10) to form a connection between the second encoder (10) and the hollow shaft (05).

9. The angle measurement system according to claim 1, characterized in that: The first encoder (09) and the second encoder (10) are both installed in the housing (06) via a transition bracket (7).

10. A precision control method for an angle measurement system according to any one of claims 1 to 9, characterized in that: The following steps are involved: A target (11) is pre-arranged on the final gear (01), and a laser tracker (12) is provided for measuring the coordinate position of the target (11); In the initial state, the coordinates of the target are measured by the laser tracker (12) to be P1=(X1, Y1), and the reading θ of the first encoder (09) and the reading ψ of the second encoder (10) are both 0; When the final gear (01) is rotated clockwise or counterclockwise, the coordinate P of the target is measured within one rotation range. i =(X i ,Y i ), and when the final gear (01) is rotated clockwise, record the reading of the first encoder (09) θ i , while rotating the final gear (01) counterclockwise, record the reading of the second encoder (10) ψ i , where i is the discrete point that the target passes through during one rotation of the final gear (01); According to the coordinates of multiple points Pi = (Xi, Yi) fitting a standard circle, the center of the target rotation O (X0, Y0) is obtained. Then the theoretical measurement angle of clockwise or counterclockwise rotation satisfies: When the final gear (01) is rotated clockwise, the error between the reading of the first encoder (09) and the theoretical measurement angle is: Δ i =θ i -α i , and fit the continuous function Δ1 according to the discrete error value; When the final gear (01) is rotated counterclockwise, the error between the reading of the second encoder (10) and the theoretical measurement angle is: Δ i =ψ i -α i , and fit the continuous function Δ2 according to the discrete error value; When the final gear (01) is rotated clockwise, the reading of the first encoder (09) after error compensation correction is θ+Δ1, and the angle of the final gear (01) that rotates continuously clockwise is corrected by the correction value θ+Δ1 of the reading of the first encoder (09) to complete the error compensation; When the final gear (01) rotates counterclockwise, the reading of the second encoder (10) after error compensation correction is ψ+Δ2, and the angle of the final gear (01) that rotates continuously counterclockwise completes the error compensation through the correction value ψ+Δ2 of the reading of the second encoder (10).

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