Method for improving general motion precision of heavy-load forming robot based on regulation and control spinor

Abstract

The invention relates to a regulation and control spinor-based heavy-load forming robot general motion precision improvement method, which comprises the following steps of S1, obtaining a standard motion spinor of an active pair and a normal motion spinor of a passive pair positioning surface, the regulation and control spinor is defined as a basic motion description quantity which is introduced through structure adjustability and can form an independent degree of freedom in a space motion system; s2, constructing a general regulation and control spinor system of a branched chain level; s3, determining an output end regulation and control spinor system and carrying out regulation and control dimension analysis; s4, based on the output end regulation and control spinor system, evaluating the error adjustable dimension expansion effect caused by different regulation and control spinor combinations at the output end, and determining the optimal kinematic pair compensation spinor number and combination; and S5, determining an iteration error correction model and an optimization strategy based on the nominal parameters. According to the method, the degree-of-freedom correction mechanism of the structural hierarchy is realized by introducing the regulation and control spinor, and the precision of the robot in the pose output process is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of advanced manufacturing technology, and more specifically, to a method for improving the general motion accuracy of heavy-duty forming robots based on the control of spin. Background Technology

[0002] With the increasing demand for high-performance manufacturing, parallel robots, characterized by high rigidity and low inertia, have been widely used in high-speed and precision applications, such as automated handling, complex forming, and assembly. The motion accuracy of parallel robots is a key factor limiting their system performance improvement. Currently, error compensation to correct the kinematic errors (machining errors, assembly errors, and drive errors) of parallel robots is an effective method to improve their motion accuracy. However, most methods rely on adjustments to the actuators in the degrees of freedom of motion, only correcting errors related to the actuators and not applicable to non-drive dimensions. Furthermore, to achieve good motion accuracy, traditional methods typically require high-precision identification of mechanism parameters, which is often difficult to meet in actual assembly processes, leading to model matching distortion, affecting the correction effect, and limiting engineering feasibility. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a general motion accuracy improvement method for heavy-duty forming robots based on the control of spin, which expands the ability to correct motion errors and improves the accuracy of the robot in the pose output process.

[0004] The technical solution adopted by this invention to solve its technical problem is: to construct a general motion accuracy improvement method for heavy-duty forming robots based on the control of spin, including the following steps:

[0005] S1. Obtain the standard motion screw of the active pair and the normal motion screw of the positioning surface of the passive pair. Define the control screw as the basic motion description quantity that can form an independent degree of freedom in the spatial motion system through structural adjustability.

[0006] S2. Construct a general control spinor system at the branch level;

[0007] S3. Determine the output control spinor system and perform controllable dimension analysis;

[0008] S4. Based on the output-end control screw system, evaluate the effect of different control screw combinations on the adjustable dimension expansion of the error at the output end, and determine the optimal number and combination of kinematic pair compensation screws.

[0009] S5. Determine the iterative error correction model and optimization strategy based on the nominal parameters.

[0010] According to the above scheme, in step S1, the control spin of the active pair is expressed as:

[0011]

[0012] In the formula, s represents the unit vector along the axis of the spinning spinor, r represents the position vector of any point on the axis of the spinning spinor in the reference coordinate system, and h is called the spinor pitch.

[0013] The control spin of the active pair is expressed as:

[0014]

[0015] According to the above scheme, in step S2, the spinor system of the branch is represented as follows:

[0016]

[0017] In the formula, S ij f represents the spinor of the j-th kinematic pair on the i-th branch. li represents the degrees of freedom of motion of the branch, and dim represents the dimension of the spinor system.

[0018] According to the above scheme, in step S2, the control spinor system of the branch is expressed as:

[0019]

[0020] In the formula, This represents the control spinor of the k-th kinematic pair on the i-th branch. This represents the dimension of the control spinor system of the branch.

[0021] According to the above scheme, in step S2, the spinor system of the branch caused by the spinor control of the kinematic pair is represented as follows:

[0022]

[0023] In the formula, This indicates that m control screws are selected from the compensating screw system without considering the order of arrangement; if m = k, then the screw system of branched motion caused by the control screws is expressed as:

[0024]

[0025] In the formula, f i max This represents the maximum degree of freedom of the branch after the introduction of the control spinor.

[0026] According to the above scheme, in step S3, the motion screw system at the robot output end is the intersection of the motion screw systems of each branch, expressed as:

[0027]

[0028] In the formula, f i This represents the degrees of freedom at the robot's output end.

[0029] According to the above scheme, in step S3, after introducing the control screw, the motion screw system at the robot output end is expressed as:

[0030]

[0031] In the formula, f a This represents the degrees of freedom at the robot's output end after the introduction of a control spinor.

[0032] According to the above scheme, in step S4, the number of compensation positions is obtained based on the correlation between the branch motion screw system caused by partial control screws and the robot motion screw system caused by all control screws, expressed as:

[0033]

[0034] The relationship between the kinematic screw system and the control screw system is defined as follows:

[0035]

[0036] According to the above scheme, in step S5, the robot's input-output relationship is as follows:

[0037]

[0038] In the formula, q e =q + Δq = [q1 + Δq1, ..., q i +Δq i ] represents the actual input value of the actuator, Δq i This indicates the input error of the actuator. D represents the modulatory amplitude of the nth control spin in the i-th limb; e =D+ΔD is the actual parameter of the robot's mechanical parts, and ΔD represents the manufacturing and assembly error of the mechanical parts.

[0039] According to the above scheme, in step S5, the maximum motion error in the robot's motion space is taken as the optimization target, and the range of the control spin adjustment amplitude is taken as the constraint condition. The optimal adjustment value of Youku spin is obtained through the optimization algorithm.

[0040] The method for improving the general motion accuracy of heavy-duty forming robots based on the control of spinor, as described in this invention, has the following beneficial effects:

[0041] This invention introduces a mechanism to correct the degrees of freedom at the structural level by adjusting spindles, effectively improving the accuracy of the robot during pose output. Without relying on fine-grained error modeling, the iterative optimization path built based on nominal design parameters significantly avoids the problems of high parameter coupling and cumbersome modeling processes in traditional methods. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0043] Figure 1 This is a schematic diagram of a single-drive 3-RSS / S parallel heavy-duty forming machine.

[0044] Figure 2 This is a coordinate relationship diagram of a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0045] Figure 3 This is an error transmission diagram for a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0046] Figure 4 This is a schematic diagram of the motion spinor system and the compensation spinor system of a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0047] Figure 5 This is a schematic diagram illustrating an error case of a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0048] Figure 6 This is a schematic diagram illustrating the error compensation effect of a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0049] Figure 7 This is a schematic diagram of the error compensation experimental setup for a single-drive 3-RSS / S parallel heavy-duty forming machine;

[0050] Figure 8 This is a schematic diagram of the theoretical motion curve and the actual motion curve after error compensation;

[0051] Figure 9 This is a schematic diagram of the rotation angle error of the motion platform after the second iteration error correction. Detailed Implementation

[0052] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0053] The method for improving the general motion accuracy of heavy-duty forming robots based on the control of spin quantity of the present invention includes the following steps:

[0054] S1. Basic Definition and Construction Principle of Controllable Screws. For the seven basic kinematic pair types of heavy-duty forming robots, this method introduces two highly engineering-feasible controllable screws based on screw theory: one is the standard kinematic screw of the active pair, and the other is the normal kinematic screw of the positioning surface of the passive pair. The controllable screw is defined here as a basic kinematic descriptor introduced through structural adjustability, capable of forming independent degrees of freedom in a spatial motion system.

[0055] According to the above definition, the control spinor of the active pair can be expressed as:

[0056]

[0057] In the formula, s represents the unit vector along the axis of the spinning spinor, r represents the position vector of any point on the axis of the spinning spinor in the reference coordinate system, and h is called the spinor pitch.

[0058] The control spinor of a passive pair can be expressed as:

[0059]

[0060] This step completes the definition of the control screw at the kinematic pair level for the robot, laying the foundation for the subsequent construction of a general control screw system.

[0061] S2. Construction of the General Controlled Screw System at the Branch Level. After defining the controlled screws of the basic kinematic pairs, it is necessary to further establish their general controlled screw system at the branch level and analyze the compensation capability of the controlled screws. Based on the definition of the controlled screws of the basic kinematic pairs, the kinematic screw system and the controlled screw system of the branch can be derived. The kinematic screw system of the branch can be expressed as:

[0062]

[0063] In the formula, S ij f represents the spinor of the j-th kinematic pair on the i-th branch. li Let represent the degrees of freedom of motion of the branch, and dim represent the dimension of the spinor system. The control spinor system of the branch can be expressed as:

[0064]

[0065] In the formula, This represents the control spinor of the k-th kinematic pair on the i-th branch. Let represent the dimension of the control screw system of the branch. According to (3) and (4), assuming that each branch of the robot is equipped with an actuator and remains in a locked state, the screw system of the branch caused by the control screw of the kinematic pair can be expressed as:

[0066]

[0067] In the formula, This indicates that m control screws are selected from the compensated screw system without considering the order of arrangement. Therefore, there are m! / (km)! cases for the branched motion screw system. If m = k, then the branched motion screw system caused by the control screws can be expressed as:

[0068]

[0069] In the formula, f i max This represents the maximum degree of freedom of the branch after the introduction of the control spinor.

[0070] This step completed the quantitative construction of the branch compensation capability and established the basic structure for the derivation of the output-end control spinor system.

[0071] S3. Derivation and Adjustable Dimension Analysis of the Output-End Controlled Screw System. Based on screw theory, the controlled screw system of the robot's output end is further derived, and the robot's error controllable dimension and the required number of controlled screws are analyzed accordingly. Based on screw theory, the motion screw system of the robot's output end is the intersection of the motion screw systems of each branch, which can be expressed as:

[0072]

[0073] In the formula, f i This represents the degrees of freedom at the robot's output end. From equations (5) and (6), after introducing the control screw, the motion screw system at the robot's output end can be expressed as:

[0074]

[0075] In the formula, f a This represents the degree of freedom at the robot's output end after introducing the control screw. When m = k, the maximum adjustable degree of freedom generated by introducing the control screw at the robot's output end can be obtained from equation (8), which is the correction dimension. Based on the above derivation, it can be seen that this method does not rely on workspace samples and does not screen existing error distributions based on similarity. The proposed method is entirely based on screw space algebra, does not involve empirical sample weight functions and interpolation calculations, and has clear structural interpretability and forward design capability.

[0076] S4. Optimization of Screw Combinations and Derivation of the Number of Screw Positions. Based on the output-end screw system, the effect of different screw combinations on the adjustable dimension expansion of the error at the output end is evaluated to determine the optimal number and combination of screws for kinematic pair compensation. Based on the correlation between the screw system of branch motion caused by some screws and the screw system of robot motion caused by all screws, the number of compensation positions can be obtained, which can be expressed as:

[0077]

[0078] The control spinor of the same branch cannot be used repeatedly to correct different compensation positions. In order to have as many correction positions as possible, the motion spinor system and the control spinor system are combined starting from m=1 to verify whether they satisfy formula (9). Control spinors that satisfy formula (9) are eliminated until m=kn, where n is the number of control spinors eliminated.

[0079] According to equations (7) and (8), the relationship between the kinematic spinor system and the control spinor system can be defined as follows:

[0080]

[0081] when The robot's control screw system belongs to its original motion screw system. The fact that the control screw system contains at least one screw that does not belong to the original motion screw system indicates that the application of control screws can expand the error compensation range of low-degree-of-freedom robots. Clearly, utilizing the concept of control screws can effectively alleviate the problem of uncorrectable errors in low-degree-of-freedom robots based on updated control models, which has significant value for the extended maintenance and corrective design of low-degree-of-freedom mechanisms.

[0082] S5. Iterative Error Correction Model and Optimization Strategy Based on Nominal Parameters. After constructing the output-end control screw system, to achieve quantitative correction of motion errors, an iterative optimization method based on nominal parameters is further proposed to calculate the adjustment amount of each control screw.

[0083] Inverse kinematics (IK) is a general method for identifying the input-output relationship of a robot. Although the IK operations differ among various robots, closed-form methods can typically obtain the relationship between the displacement / rotation of the driving kinematic pairs and the pose of the output end. Therefore, it is reasonable to assume that the robot's input-output relationship is as follows:

[0084]

[0085] In the formula, q = [q1, ..., q i [] represents the input value of the actuator, D represents the array of all design parameters affecting the motion of the output, and Q represents the pose of the output, which can be represented as:

[0086]

[0087] Considering the actuator's drive error, assembly error, manufacturing error of mechanical parts, and the input q of the control spindle. c The transformation matrix Q of the correction error c By incorporating kinematic errors into the robot's input-output relationship, the robot's input-output relationship can be rewritten as follows:

[0088]

[0089] In the formula, q e =q + Δq = [q1 + Δq1, ..., q i +Δq i ] represents the actual input value of the actuator, Δq i This indicates the input error of the actuator. D represents the modulatory amplitude of the nth control spin in the i-th limb. e =D+ΔD is the actual parameter of the robot's mechanical parts, and ΔD represents the manufacturing and assembly error of the mechanical parts.

[0090] Using the maximum motion error in the robot's motion space as the optimization objective and the range of the screw adjustment amplitude as the constraint, the optimal adjustment value of the Youku screw is obtained through an optimization algorithm. Let H be the main objective function, and the objective function based on real parameters can be constructed as follows:

[0091]

[0092] According to equation (14), under the condition of known robot kinematic error, the adjustment amplitude q of the control spindle with minimum motion error can be obtained by iterative calculation. c To avoid the difficulty of error identification, an optimization model based on nominal parameters was further constructed, the expression of which is:

[0093]

[0094] Based on equations (19) and (20), the proposed optimization process sequentially calculates and filters the dependent variables and minimizes the pose deviation at the output end. The control screw is then numerically adjusted accordingly to complete the motion error correction. For the kinematic pair involved in the correction at the output end, its control screw is q. c Then its contribution to the correction of the pose at the output end can be expressed as:

[0095] ΔQ(q,q c ,D)=q c S a (16)

[0096] The final pose correction effect at the output is the result of synthesizing all the control screw adjustments:

[0097] Q c =Q + ΔQ (17)

[0098] The method proposed in this invention allows the output error to be mapped to a physically controllable kinematic pair regulator, i.e., a screw variable, without any prediction process based on sample interpolation. Furthermore, this method does not rely on workspace samples, nor does it screen existing error distributions based on similarity. It is entirely based on screw space algebra, without involving empirical sample weighting functions or interpolation calculations, and possesses clear structural interpretability and forward design capabilities. Compared to existing methods that "rely on spatial sample data + vector weighted regression," this model has the following advantages: 1) It is entirely based on an analytical model of robot kinematics, requiring no additional sampling points; 2) After introducing the screw variable, a global objective function can be directly constructed; 3) The control dimension can be optimized to the optimal solution in the task-related space, supporting pre-design rather than post-hoc correction.

[0099] Based on the steps of the above-described method for improving robot motion accuracy based on spin control, the following section, with reference to the accompanying drawings, uses a single-drive 3-RSS / S parallel heavy-duty forming machine as a case study to conduct structural modeling and error correction experiments. The basic structure of the single-drive 3-RSS / S parallel heavy-duty forming machine is as follows: Figure 1 As shown in Table 1, the basic design parameters are as follows.

[0100] The structure of the parallel heavy-duty forming machine consists of a driver, a 3-RSS / S parallel mechanism, a mold, a hydraulic system, and a machine tool frame. Figure 2 The structural layout of the proposed mechanism is shown. S0(x0y0z0) is a coordinate system attached to the machine tool base, and S1(x1y1z1) and S... b (x b y b z b (A) represents the coordinate system of the output end and the mold, respectively. Where A... i B indicates the center position of the revolute joint fixed on the base. i This indicates the center position of the ball joint S on the revolute joint. C i This indicates the center of the lower S-shaped ball joint on the end platform. i The length of each linkage is represented by r, where h is the vertical distance between the base and the end platform. a r b and r c A respectively i B i and C i The extreme diameters of (i = 1, 2, 3). While keeping the lengths of each link constant, the geometric constraints of the single-drive 3-RSS / S parallel mechanism are:

[0101]

[0102] In the formula, a i and b i They represent point A respectively. i and Bi The position vector in coordinate system S0(x0y0z0), c i Point C i The position vector in coordinate system S1(x1y1z1). Δβ1 and Δβ2 are constants, representing the numerical relationships between β1 and β2, and β2 and β3.

[0103] Table 1 Structural parameters of a single-drive 3-RSS / S parallel heavy-duty forming machine

[0104]

[0105]

[0106] Figure 3 The kinematic error transmission diagram of the active and passive branches in a single-drive 3-RSS / S parallel heavy-duty forming machine is shown. Coordinate system S A For the base, a fixed coordinate system is established, S B The S-ball joint coordinate system fixed in the revolute joint, S C The S-shaped ball joint coordinate system is fixed in the end platform. Coordinate systems Sa, Sb, and Sc are the corresponding coordinate systems considering kinematic errors. a e b e c Representing coordinate system S respectively A With S a Coordinate system S B With S b Coordinate system S C With S c The kinematic error between, e l This represents the error of the connecting rod. Therefore, the geometric constraints of the single-drive 3-RSS / S parallel heavy-duty forming machine considering motion errors can be rewritten as:

[0107]

[0108] In the formula, Δl i This represents the length error of the connecting rod. The motion error at the output end is determined by 39 motion error terms, including 36 active branch motion error terms and 3 passive branch motion error terms.

[0109] like Figure 4 As shown, for each active branch RSS, S i1 S is the kinematic spinor of the revolute joint. i2 S i3 and S i4 S represents the kinematic rotation of the ball joint fixed on the revolute joint. i5 S i6 and S i7 The spinor of the ball joint S fixed on the end platform is called the spinor.i2 and S i5 They are linearly dependent because their axes are collinear and their pitch is zero. The direction vector of each active branch link is defined as e. i1 The normal vector of the plane passing through the linkage mechanism and the center of S0 is e. i2 , and vector e i1 and e i2 The orthogonal vector is e i3 , can be represented as:

[0110]

[0111] Therefore, the spinors of each kinematic pair in the active branched RSS should be:

[0112]

[0113] The control spinor system of an active branched RSS can be expressed as:

[0114]

[0115] The control spinor system of a passive branch can be expressed as:

[0116]

[0117] According to formulas (19) and (20), the active branched motion spinor system caused by the introduction of the control spinor can be expressed as:

[0118]

[0119] According to formulas (19) and (21), the passive branched motion spinor system caused by the introduction of the control spinor can be expressed as:

[0120]

[0121] Combining formulas (22) and (23), the motion screw system of a single-drive 3-RSS / S parallel heavy-duty forming machine caused by the introduction of controlled screw can be expressed as:

[0122]

[0123] Clearly, the application of spinor manipulation can expand the error compensation range (f) of low-degree-of-freedom parallel robots. a =4)>(f=3). According to formula (10), the number of error compensation positions for the single-drive 3-RSS / S parallel heavy-duty forming machine is 2. In this embodiment, the motion performed by the single-drive 3-RSS / S parallel heavy-duty forming machine is a multi-degree-of-freedom swing motion, which can be expressed as:

[0124]

[0125] In this embodiment, θ = 1.5π / 180, φ = 2πt. t represents time.

[0126] against Figure 5 The error given in the formula (15) is used to perform global optimization in order to explore the effect of global optimal correction based on nominal parameters. Figure 6 Shown in E z The impact of the globally optimal error correction method based on nominal and actual parameters on motion error under the condition that E = 0. The results show that after global optimal correction, E... z The errors are significantly reduced in the four cases where the value is 0. Specifically, for case 1, the maximum motion error on the x-axis decreases from 0.2468 degrees to 0.0387 degrees; for case 2, the maximum motion error on the y-axis decreases from 0.2160 degrees to 0.0245 degrees; for case 3, the maximum motion error on the z-axis decreases from 2.0876 degrees to 0.3201 degrees; and for case 4, the maximum motion errors on the x-axis, y-axis, and z-axis decrease from 0.1 degrees, 0.1 degrees, and 0.5 degrees to 0.0182 degrees, 0.0598 degrees, and 0.0602 degrees, respectively. By comparing the motion error curves after correction using the globally optimal error correction method based on nominal and actual parameters, it can be observed that there is no significant difference in the maximum motion error at the output end. This indicates that the proposed globally optimal error correction method based on nominal parameters is effective.

[0127] Furthermore, the position and pose data of the output end are obtained using a laser tracker, and the experimental setup and calibration principle are calibrated as follows: Figure 7 As shown. Based on the calibration data at the output, a second-order iterative error correction experiment based on the nominal parameters was conducted. Figure 8 This refers to the theoretical rotation angle at the output after the second iteration based on the nominal parameters, and the calibrated rotation angle. Figure 9 This represents the rotation angle error of the motion platform after the second iteration error correction. Experimental data shows that after two rounds of screw adjustment based on nominal parameters, the theoretical attitude curve at the output end highly matches the measured trajectory. The maximum attitude deviation is reduced to within 0.16 degrees, and the overall output stability is improved by more than 60%.

[0128] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for improving the general motion accuracy of heavy-duty forming robots based on the control of spinor, characterized in that, Includes the following steps: S1. Obtain the standard motion screw of the active pair and the normal motion screw of the positioning surface of the passive pair. Define the control screw as the basic motion description quantity that can form an independent degree of freedom in the spatial motion system through structural adjustability. S2. Construct a general control spinor system at the branch level; S3. Determine the output control spinor system and perform controllable dimension analysis; S4. Based on the output-end control screw system, evaluate the effect of different control screw combinations on the adjustable dimension expansion of the error at the output end, and determine the optimal number and combination of kinematic pair compensation screws. S5. Determine the iterative error correction model and optimization strategy based on the nominal parameters.

2. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 1, characterized in that, In step S1, the control spin of the active pair is expressed as: In the formula, s represents the unit vector along the axis of the spinning spinor, r represents the position vector of any point on the axis of the spinning spinor in the reference coordinate system, and h is called the spinor pitch. The control spin of the active pair is expressed as:

3. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 2, characterized in that, In step S2, the spinor system of the branch is represented as: In the formula, S ij f represents the spinor of the j-th kinematic pair on the i-th branch. li represents the degrees of freedom of motion of the branch, and dim represents the dimension of the spinor system.

4. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 2, characterized in that, In step S2, the control spinor system of the branch is expressed as: In the formula, This represents the control spinor of the k-th kinematic pair on the i-th branch. This represents the dimension of the control spinor system of the branch.

5. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spin as described in claim 2, characterized in that, In step S2, the spinor system of the branch caused by the spinor control of the kinematic pair is represented as: In the formula, This indicates that m control screws are selected from the compensating screw system without considering the order of arrangement; if m = k, then the screw system of branched motion caused by the control screws is expressed as: In the formula, f i max This represents the maximum degree of freedom of the branch after the introduction of the control spinor.

6. The method for improving the general motion accuracy of heavy-duty forming robots based on the control of spinor as described in claim 5, characterized in that, In step S3, the spinor system at the robot's output end is the intersection of the spinor systems of each branch, expressed as: In the formula, f i This represents the degrees of freedom at the robot's output end.

7. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 6, characterized in that, In step S3, after introducing the control screw, the motion screw system at the robot output is expressed as: In the formula, f a This represents the degrees of freedom at the robot's output end after the introduction of a control spinor.

8. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 7, characterized in that, In step S4, the number of compensated positions is obtained based on the correlation between the branch motion screw system caused by partial control screws and the robot motion screw system caused by all control screws, expressed as: The relationship between the kinematic screw system and the control screw system is defined as follows:

9. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 8, characterized in that, In step S5, the robot's input-output relationship is as follows: In the formula, q e =q + Δq = [q1 + Δq1, ..., q i +Δq i ] represents the actual input value of the actuator, Δq i This indicates the input error of the actuator. D represents the modulatory amplitude of the nth control spin in the i-th limb; e =D+ΔD is the actual parameter of the robot's mechanical parts, and ΔD represents the manufacturing and assembly error of the mechanical parts.

10. The method for improving the general motion accuracy of heavy-duty forming robots based on controlled spinor as described in claim 9, characterized in that, In step S5, the maximum motion error in the robot's motion space is taken as the optimization objective, and the range of the control spinor adjustment amplitude is taken as the constraint condition. The optimal adjustment value of the Youku spinor is obtained through the optimization algorithm.

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