A high-precision large-scale multi-degree-of-freedom deployment arm adjustment method

Abstract

The application provides a high-precision large-scale multi-degree-of-freedom deployment arm assembling and adjusting method, which can effectively eliminate the influence of ground gravity on the deployment precision of the deployment arm, and makes the assembling and adjusting precision of the ten-meter-level deployment arm reach the order of magnitude of one percent. The application increases the process of adjusting the pose of the tool in advance, controls the joint position of the deployment arm within a certain range, and then performs fine adjustment to improve the assembling and adjusting efficiency. Meanwhile, the six-degree-of-freedom parallel mechanism is used to connect the joint of the deployment arm to adjust the pose, and the theoretical position is quickly and conveniently adjusted. On the basis of the assembling and adjusting under a single pose, the iterative step of eliminating the zero-gravity unloading error is added, the deployment arm is unloaded in two perpendicular directions respectively, the deployment arm is unloaded by 100% in the direction perpendicular to the gravity, and the assembling precision is repeatedly measured and adjusted in the two gravity unloading states, so that the assembling effect consistent with the on-orbit zero-gravity state is achieved, and the assembling and adjusting precision of the deployment arm is improved.

Description

Technical Field

[0001] This invention relates to a high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method, belonging to the aerospace field. Background Technology

[0002] The design and implementation of spacecraft mechanism assembly and adjustment methods have always been crucial to ensuring the final accuracy of the deployable arm. With the development of aerospace technology and the continuous improvement of requirements, spacecraft mechanisms are evolving towards higher precision, larger scale, and more degrees of freedom, resulting in increasingly complex deployable arm joint structures. This places higher demands on assembly and adjustment methods. Currently, commonly used deployable arm assembly and adjustment methods typically involve manual adjustment in a single attitude. For deployable arms with complex structures and high spatial attitude accuracy requirements, this is extremely time-consuming and inefficient.

[0003] By conducting error analysis on a 10-meter-class deployable arm, the overall accuracy requirements of the deployable arm are decomposed into two parts: angular error and displacement error, which are then discussed.

[0004] An analysis of its angular error factors mainly includes two parts: constant error and thermal deformation error. The constant error consists of the repeatability of the deployable arm's pointing accuracy and residual assembly and adjustment errors. The angular repeatability of a ten-meter-class deployable arm is typically within 10... -3 In terms of measurement, the thermal deformation error mainly depends on the relatively fixed material properties of the deployable arm, while the residual assembly error is within 10. -2 The metric level largely determines the final angular accuracy of the deployable arm.

[0005] An analysis of its displacement error factors reveals that it mainly consists of three parts: the thermal deformation error of the deployable arm, the residual error of assembly and adjustment, and the repeatability accuracy of the deployable arm. The displacement repeatability accuracy of a 10-meter-class deployable arm is typically within 10. -1 On the order of millimeters, thermal deformation error depends on relatively fixed material properties, while assembly residual error is within 10. 0 The millimeter-level accuracy largely determines the final displacement precision of the deployable arm.

[0006] Therefore, the magnitude of the residual error in assembly and adjustment will greatly affect the final overall accuracy of the deployable arm, so it is necessary to design a method that can achieve high-precision assembly and adjustment of the deployable arm.

[0007] In addition, in order to ensure the accuracy of the deployable arm in the final zero-gravity state in orbit, it is usually assembled in a state of zero-gravity unloading using air-bearing support. Under this attitude, the unloading efficiency in the gravity direction will have errors and it is difficult to achieve 100% accurate unloading, which leads to a difference between the accuracy of ground assembly and adjustment and the accuracy of the actual in-orbit application state.

[0008] Previously, the assembly and adjustment method, which involved manual adjustment in a single attitude, was acceptable for shorter deployable arms with lower precision requirements. The accuracy was affected by the zero-gravity unloading efficiency on the ground, and the initial ground-based assembly and adjustment could meet the final on-orbit accuracy requirements. However, for large-scale deployable arms in the tens of meters range, the manual assembly and adjustment method in a single attitude has reached its physical limits. It is difficult to achieve high precision during ground assembly and adjustment. Due to the influence of the zero-gravity unloading efficiency during the ground assembly and adjustment process, even if the deployable arm is successfully assembled and adjusted on the ground, its accuracy will change significantly during on-orbit application, failing to meet the ultra-high precision requirements. At the same time, manual adjustment is very time-consuming and inefficient. Summary of the Invention

[0009] The technical problem to be solved by this invention is that for large-scale multi-degree-of-freedom deployable arms with complex structures and high spatial pose accuracy requirements, traditional single-attitude assembly and adjustment methods are difficult to meet the accuracy requirements, and the ultra-high accuracy requirements are difficult to achieve manually, thus failing to meet the needs of high precision and high efficiency. In order to solve the above problems, this invention provides a high-precision large-scale multi-degree-of-freedom deployable arm assembly and adjustment method.

[0010] The technical solution adopted in this invention is: a high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method, comprising:

[0011] S1: Adjust the tooling simulation wall to the theoretical position;

[0012] S2: Assemble the deployable arm onto the tooling simulation wall;

[0013] S3: Perform the first positional accuracy adjustment of the unfolded arm joint: Measure and adjust the spatial position of the joint to be assembled so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements.

[0014] S4: Perform a second retest and adjustment of the pose accuracy of the extended arm joint;

[0015] S5: An iterative optimization method is used to eliminate zero-gravity unloading error.

[0016] Furthermore, adjusting the tooling simulation wall to the theoretical position includes:

[0017] Determine the posture of the first assembly and adjustment of the boom, calculate and determine the theoretical spatial position of the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted, and calculate the theoretical relative position between the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted.

[0018] Design a tooling simulation wall to match the interface of the reference joint and the flange mounting surface of the joint to be installed;

[0019] Using the theoretical relative position between the measured reference joint flange mounting surface and the flange mounting surface of the joint to be installed as the standard, and taking the tooling simulation wall of the reference joint as the reference, the tooling simulation wall of the joint to be installed is adjusted to the theoretical position, and the error is controlled within the set threshold range.

[0020] Furthermore, the assembly of the unfolding arm to the tooling simulation wall includes:

[0021] Assemble the reference joint, arm, and joint to be installed. Connect the reference joint and the joint to be installed to the corresponding tooling simulation wall. Use the zero-gravity unloading tool to unload the deployable arm by gravity and ensure that the connecting pins of the reference joint, the joint to be installed, and the tooling simulation wall can be inserted and removed.

[0022] Remove the tooling simulation wall that is to be installed and adjusted.

[0023] Furthermore, the second retest and adjustment of the pose accuracy of the extended arm joint includes:

[0024] Using the state after the entire deployable arm has rotated 90° around the central axis of the arm as the theoretical position for the second pose accuracy adjustment, a new tooling simulation wall is designed to match the interface of the reference joint flange mounting surface after the entire deployable arm has rotated 90°.

[0025] After rotating the entire deployable arm 90° around the central axis of the arm, connect the reference joint to the new tooling simulation wall, use the zero-gravity unloading tool to unload the deployable arm by gravity, and ensure that the connecting pins between the reference joint and the new tooling simulation wall can be inserted and removed.

[0026] The spatial position of the joint to be assembled is remeasured and adjusted so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements.

[0027] Furthermore, the method of eliminating zero-gravity unloading error through iterative optimization includes:

[0028] Rotate the entire outstretched arm -90° around the central axis of the arm to return to the S3 state;

[0029] Repeat steps S3 and S4 to re-measure and adjust the spatial position of the joint to be assembled until the re-measurement results meet the theoretical assembly accuracy requirements and no further adjustment is needed.

[0030] Furthermore, the aforementioned high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method also includes:

[0031] When there are ≥2 joints to be installed and adjusted with a span of 10 meters between the outstretched arms, continue to adjust the positional accuracy of the subsequent joints to be installed and adjusted: keep the reference joint unchanged, and use the reference joint as the reference to adjust the positional accuracy of the new joints to be installed and adjusted. Repeat S1 to S5 in a loop until the positional adjustment of all joints of the outstretched arm is completed.

[0032] The advantages of this invention compared to the prior art are:

[0033] (1) The present invention proposes that before assembling the deployable arm joint, the reference joint and the tooling simulation wall of the joint to be assembled and adjusted should be adjusted to the theoretical position, and then the deployable arm joint should be assembled to ensure that the connecting pins of the joint and the simulation wall can be easily inserted and removed, thereby indirectly ensuring the assembly accuracy of the joint through the tooling and improving the assembly efficiency.

[0034] (2) This invention proposes to add an optimized iterative step to eliminate zero-gravity unloading error on the basis of single-position assembly and adjustment. The precision of the deployable arm is repeatedly measured and adjusted. That is, the deployable arm is rotated 90° around the axis of the arm rod to measure and adjust the precision. Since there is an error when the deployable arm is unloaded under zero gravity, it is impossible to achieve 100% accurate unloading. In this way, the direction of gravity during the previous assembly and adjustment is rotated to the horizontal direction, which effectively eliminates the assembly and adjustment error caused by the zero-gravity unloading error. Then, it is rotated -90° back to the initial position to measure and adjust the precision again. This process is repeated until the large-scale deployable arm of the ten-meter scale reaches the ultra-high assembly precision requirements.

[0035] (3) This invention proposes to use a six-degree-of-freedom parallel mechanism to connect the joints of the unfolding arm for attitude adjustment, instead of the traditional manual adjustment method. By utilizing the extremely high position calculation accuracy, repeatability accuracy and extremely small comprehensive positioning error of the six-degree-of-freedom parallel mechanism, the attitude of the unfolding arm joint can be quickly and conveniently adjusted to the theoretical position, thus improving the assembly and adjustment efficiency. Attached Figure Description

[0036] Figure 1 This is a flowchart of a high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method disclosed in this invention;

[0037] Figure 2 This is a schematic diagram of the first fine-tuning of the end joint's pose.

[0038] Figure 3 This is a schematic diagram of the second fine-tuning of the end joint's pose. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific examples, but the implementation of the present invention is not limited thereto.

[0040] A high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method includes the following steps:

[0041] S1: Adjust the tooling simulation wall to the theoretical position;

[0042] S2: Assemble the deployable arm onto the tooling simulation wall;

[0043] S3: Perform the first positional accuracy adjustment of the unfolded arm joint: Measure and adjust the spatial position of the joint to be assembled so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements.

[0044] S4: Perform a second retest and adjustment of the pose accuracy of the extended arm joint;

[0045] S5: An iterative optimization method is used to eliminate zero-gravity unloading error.

[0046] The adjustment of the tooling simulation wall to the theoretical position includes:

[0047] Determine the posture of the first assembly and adjustment of the boom, calculate and determine the theoretical spatial position of the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted, and calculate the theoretical relative position between the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted.

[0048] Design a tooling simulation wall to match the interface of the reference joint and the flange mounting surface of the joint to be installed;

[0049] Using the theoretical relative position between the measured reference joint flange mounting surface and the flange mounting surface of the joint to be installed as the standard, and taking the tooling simulation wall of the reference joint as the reference, the tooling simulation wall of the joint to be installed is adjusted to the theoretical position, and the error is controlled within the set threshold range.

[0050] The assembly deployment arm to the tooling simulation wall includes:

[0051] Assemble the reference joint, arm, and joint to be installed. Connect the reference joint and the joint to be installed to the corresponding tooling simulation wall. Use the zero-gravity unloading tool to unload the deployable arm by gravity and ensure that the connecting pins of the reference joint, the joint to be installed, and the tooling simulation wall can be inserted and removed.

[0052] Remove the tooling simulation wall that is to be installed and adjusted.

[0053] The second pose accuracy retest and adjustment of the extended arm joint includes:

[0054] Using the state after the entire deployable arm has rotated 90° around the central axis of the arm as the theoretical position for the second pose accuracy adjustment, a new tooling simulation wall is designed to match the interface of the reference joint flange mounting surface after the entire deployable arm has rotated 90°.

[0055] After rotating the entire deployable arm 90° around the central axis of the arm, connect the reference joint to the new tooling simulation wall, use the zero-gravity unloading tool to unload the deployable arm by gravity, and ensure that the connecting pins between the reference joint and the new tooling simulation wall can be inserted and removed.

[0056] The spatial position of the joint to be assembled is remeasured and adjusted so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements.

[0057] The method of eliminating zero-gravity unloading error using iterative optimization includes:

[0058] Rotate the entire outstretched arm -90° around the central axis of the arm to return to the S3 state;

[0059] Repeat steps S3 and S4 to re-measure and adjust the spatial position of the joint to be assembled until the re-measurement results meet the theoretical assembly accuracy requirements and no further adjustment is needed.

[0060] A high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method, further comprising:

[0061] When there are ≥2 joints to be installed and adjusted with a span of 10 meters between the outstretched arms, continue to adjust the positional accuracy of the subsequent joints to be installed and adjusted: keep the reference joint unchanged, and use the reference joint as the reference to adjust the positional accuracy of the new joints to be installed and adjusted. Repeat S1 to S5 in a loop until the positional adjustment of all joints of the outstretched arm is completed.

[0062] Example:

[0063] like Figure 2 , Figure 3 As shown, the high-precision, large-scale, multi-degree-of-freedom deployable arm has high precision requirements. After full deployment, the distance between the root joint 4-1 and the end joint 4-2 reaches 11 meters. The deployment process involves six degrees of freedom of motion. Therefore, the high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method disclosed in this invention is selected for assembly and adjustment.

[0064] like Figure 1 The assembly and adjustment process is as follows:

[0065] Step 1: Adjust the tooling simulation wall to the theoretical position;

[0066] As a preferred method, the posture of the first assembly and adjustment of the deploying arm is determined, with the root joint 4-1 as the reference joint and the end joint 4-2 as the joint to be assembled and adjusted. Under this state, the theoretical spatial position of the flange mounting surface of the root joint 4-1 and the flange mounting surface of the end joint 4-2 is calculated and determined, and the theoretical relative position between the flange mounting surfaces of the two joints is calculated.

[0067] Design root joint tooling simulation wall 1-1 and end joint tooling simulation wall 1-2 to match the flange mounting surfaces of root joint 4-1 and end joint 4-2;

[0068] Using the calculated relative position between the two joint flange mounting surfaces as the standard, and taking the root joint tooling simulation wall 1-1 as a reference, adjust the end joint tooling simulation wall 1-2 to the theoretical position, and control the error within an acceptable range.

[0069] Step 2: Assemble the deployable arm onto the tooling simulation wall;

[0070] like Figure 2 Assemble the root joint 4-1, the middle unfolding arm assembly 4-3, and the end joint 4-2, and connect them to the root joint tooling simulation wall 1-1 and the end joint tooling simulation wall 1-2. Use the zero-gravity unloading tooling 3 to unload the unfolding arm by gravity.

[0071] Ensure that the connecting pins of the joint and root joint tooling simulation wall 1-1 and the end joint tooling simulation wall 1-2 can be easily inserted and removed, thereby indirectly ensuring the assembly accuracy of the joint through the tooling;

[0072] Remove the simulated wall 1-2 of the end joint tooling;

[0073] Step 3: Perform the first positional accuracy adjustment of the extended arm joint;

[0074] The spatial position of the end joint 4-2 was precisely measured and adjusted so that its positional relationship with the root joint 4-1 met the theoretical assembly accuracy requirements.

[0075] Step 4: Perform a second positional accuracy adjustment of the extended arm joint;

[0076] like Figure 3 The state after the entire extended arm is rotated 90° around the central axis of the arm is taken as the theoretical position for the second pose accuracy adjustment.

[0077] Design a new tooling simulation wall 2 to match the flange mounting surface interface of the root joint 4-1 after the unfolding arm rotates 90°.

[0078] After rotating the entire deployable arm 90°, connect it to the new tooling simulation wall 2, and use the zero-gravity unloading tooling 3 to unload the deployable arm by gravity.

[0079] Ensure that the connecting pins between the joint and the new tooling simulation wall 2 can be easily inserted and removed, thereby indirectly ensuring the assembly accuracy of the joint through the tooling;

[0080] The spatial position of the end joint 4-2 was remeasured and adjusted to ensure that its positional relationship with the root joint 4-1 meets the theoretical assembly accuracy requirements.

[0081] Step 5: Optimization iteration to eliminate zero-gravity unloading error;

[0082] Rotate the entire outstretched arm -90° to return to the state in step three;

[0083] The spatial position of end joint 4-2 was re-measured. The re-measurement results met the theoretical assembly accuracy requirements, and no further adjustment was required. Thus, the assembly and adjustment of end joint 4-2 was completed.

[0084] In this embodiment, the number of joints to be installed and adjusted, which are on the order of ten meters in length, is 1, and step six is ​​omitted;

[0085] This completes the assembly and fine-tuning process of the deployable arm.

[0086] The precision test of the deployable arm assembled using the high-precision large-scale multi-degree-of-freedom deployable arm assembly and adjustment method disclosed in this invention showed that its ground assembly and adjustment error was less than 0.005°.

[0087] The deployable arm assembled using the high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method disclosed in this invention has an on-orbit deployment accuracy error of less than 0.02° and an end displacement error of less than 5 mm.

[0088] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific implementation of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method, characterized in that, include: S1: Adjust the tooling simulation wall to the theoretical position; S2: Assemble the deployable arm onto the tooling simulation wall; S3: Perform the first positional accuracy adjustment of the extended arm joint; S4: Perform a second retest and adjustment of the pose accuracy of the extended arm joint; S5: Employ an iterative optimization method to eliminate zero-gravity unloading errors; Perform the first pose accuracy adjustment of the extended arm joint, including: Measure and adjust the spatial position of the joint to be assembled so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements; The second pose accuracy retest and adjustment of the extended arm joint includes: Using the state after the entire deployable arm has rotated 90° around the central axis of the arm as the theoretical position for the second pose accuracy adjustment, a new tooling simulation wall is designed to match the interface of the reference joint flange mounting surface after the entire deployable arm has rotated 90°. After rotating the entire deployable arm 90° around the central axis of the arm, connect the reference joint to the new tooling simulation wall, use the zero-gravity unloading tool to unload the deployable arm by gravity, and ensure that the connecting pins between the reference joint and the new tooling simulation wall can be inserted and removed. The spatial position of the joint to be assembled is remeasured and adjusted so that the positional relationship between the joint to be assembled and the reference joint meets the theoretical assembly accuracy requirements. The method of eliminating zero-gravity unloading error using iterative optimization includes: Rotate the entire outstretched arm -90° around the central axis of the arm to return to the S3 state; Repeat steps S3 and S4 to re-measure and adjust the spatial position of the joint to be assembled until the re-measurement results meet the theoretical assembly accuracy requirements and no further adjustment is needed.

2. The high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method according to claim 1, characterized in that, The adjustment of the tooling simulation wall to the theoretical position includes: Determine the posture of the first assembly and adjustment of the boom, calculate and determine the theoretical spatial position of the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted, and calculate the theoretical relative position between the mounting surface of the reference joint flange and the mounting surface of the joint flange to be assembled and adjusted. Design a tooling simulation wall to match the interface of the reference joint and the flange mounting surface of the joint to be installed; Using the theoretical relative position between the measured reference joint flange mounting surface and the flange mounting surface of the joint to be installed as the standard, and taking the tooling simulation wall of the reference joint as the reference, the tooling simulation wall of the joint to be installed is adjusted to the theoretical position, and the error is controlled within the set threshold range.

3. The high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method according to claim 2, characterized in that, The assembly deployment arm to the tooling simulation wall includes: Assemble the reference joint, arm, and joint to be installed. Connect the reference joint and the joint to be installed to the corresponding tooling simulation wall. Use the zero-gravity unloading tool to unload the deployable arm by gravity and ensure that the connecting pins of the reference joint, the joint to be installed, and the tooling simulation wall can be inserted and removed. Remove the tooling simulation wall that is to be installed and adjusted.

4. The high-precision, large-scale, multi-degree-of-freedom deployable arm assembly and adjustment method according to claim 3, characterized in that, Also includes: When there are ≥2 joints to be installed and adjusted with a span of 10 meters between the outstretched arms, continue to adjust the positional accuracy of the subsequent joints to be installed and adjusted: keep the reference joint unchanged, and use the reference joint as the reference to adjust the positional accuracy of the new joints to be installed and adjusted. Repeat S1 to S5 in a loop until the positional adjustment of all joints of the outstretched arm is completed.

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