Self-adaptive axial positioning method for shaping-free press fitting tool of solid rocket engine

Abstract

The invention relates to the technical field of solid rocket engine manufacturing, in particular to a solid rocket engine shaping-free press fitting tool self-adaptive axial positioning method, which comprises the following steps of: performing three-dimensional scanning on the outer surface of an engine through a laser distance measuring sensor which is rigidly connected with the tail end of a robot; acquiring circumferential point cloud data of at least six radial sections at equal intervals along the axial direction; performing elliptic equation fitting on the point cloud of each section in a robot control module, and solving the coordinate of the circle center of each ellipse; performing linear fitting on all ellipse centers to obtain an axial unit vector of the engine; and the robot is adjusted to the press-fitting height, the angle of a press-fitting tool is calculated through a Newton iteration method so that the angle can coincide with the unit vector, and shaping-free press-fitting operation is conducted in the vector direction. Through axial positioning of different engines, the robot can adjust the movement direction of the tail end press-fitting tool in a self-adaptive mode, and the engine shaping-free quality defect caused by the fact that the press-fitting direction does not coincide with the axial direction of the engines is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of solid rocket engine manufacturing, and more particularly to an adaptive axial positioning method for a solid rocket engine non-shaping press-fitting tool. Background Art

[0002] Since the propellant profile of a solid rocket engine is mostly a complex structural curved surface, it is difficult to shape it through traditional cutting tools. This not only leads to low shaping efficiency, reduces the accuracy of the profile, but also easily causes problems such as damage to the propellant surface. After traditional shaping, the profile of the propellant surface is irreversible and there are safety risks. Therefore, the non-shaping method can directly form a complex profile without complex shaping processes. However, the quality of the non-shaping process is affected by the axial positioning quality of the tool press-fitting.

[0003] However, existing solutions for large engines mainly rely on manual hoisting for auxiliary installation and fixation, and there are generally positioning errors, resulting in deviations between the non-shaping press-fitting tool and the engine axis. And when the non-shaping press-fitting tool only has a degree of freedom of pressing vertically downward, it cannot adapt to the axial deviation of different engines, resulting in situations such as axial pressing deviation and end face pressing skew. Therefore, by extracting the axial parameters of the fixed engine, the robot drives the press-fitting tool to adapt to the axes of different engines, thereby accurately positioning the press-fitting direction. This method can effectively improve the accuracy of the non-shaping process and product quality. Summary of the Invention

[0004] The object of the present invention is to provide an adaptive axial positioning method for a solid rocket engine non-shaping press-fitting tool, which can extract the axial parameters of the fixed engine to make the press-fitting tool adapt to the axes of different engines, thereby accurately positioning the press-fitting direction.

[0005] The technical solution adopted by the present invention to achieve the above object is: an adaptive axial positioning method for a solid rocket engine non-shaping press-fitting tool, comprising the following steps:

[0006] 1) Physical data acquisition: Use a laser range finder rigidly connected to the end of the robot to perform three-dimensional scanning on the outer surface of the engine, and equidistantly obtain the circumferential point cloud data of at least 6 radial cross-sections along the axis.

[0007] 2) Geometric parameter calculation: Fit the point cloud of each cross-section with an ellipse equation in the robot control module to solve the coordinates of the center of each ellipse.

[0008] 3) Spatial axis generation: Linearly fit all the ellipse centers by the least squares method to obtain the unit vector of the engine axis.

[0009] 4) Axial press-fitting execution: The robot is adjusted to the press-fitting height. The angle of the press-fitting tool is calculated by the Newton iteration method to make it coincide with the unit vector, and a non-shaping press-fitting operation is carried out along the vector direction.

[0010] In the step 1), the laser distance sensor is rigidly connected through the flange at the end of the robot. When scanning, the end effector of the robot moves along the engine axis at a preset speed and rotates around the Z-axis of the tool coordinate system for scanning.

[0011] The step 1) is specifically as follows:

[0012] 1-1) Establish a measurement tool coordinate system, which refers to the coordinate system where the robot is equipped with a laser distance sensor. The coordinate data of the sampling points on the radial cross-section is measured through the laser distance sensor.

[0013] 1-2) Let the measurement cross-section be γ j , the cross-section height be Z1, the sampling point be P ij , and the sampling point coordinates be (X ij , Y ij ). Each radial cross-section needs to sample at least 6 points; after each radial cross-section sampling is completed, adjust the linear motion module of the laser distance sensor to move a fixed distance h along the Z-axis for sampling of the next radial cross-section γ j+1 , until j = m, Z = Z m , that is, all samplings are completed.

[0014] 1-3) Define the sampling points of each cross-section as a column vector for fitting the cross-section equation.

[0015] In the step 1-2), the fixed distance h is:

[0016]

[0017] Among them, Z m is the upper limit of the sampling radial cross-section height, Z1 is the upper limit of the sampling radial cross-section height, and m is the number of sampling radial cross-sections.

[0018] The step 2) includes the following steps:

[0019] 2-1) Perform noise filtering processing on the point cloud data; and define the ellipse center coordinates as O j , with specific parameters (X 0j , Y 0j , Z j ); By fitting the ellipse equations of each cross-section, obtain the ellipse center coordinates of m.

[0020] 2-2) For the radial cross-section ellipse that satisfies the equation, that is:

[0021] Ax 2+Bxy + Cy 2 +Dx + Ey + F = 0

[0022] where A, B, C, D, E, and F are all constants;

[0023] 2 - 3) Substitute the coordinates of the radial cross - section sampling points, and the center coordinates of the ellipse can be calculated as:

[0024] The said step 3) includes the following steps:

[0025] 3 - 1) For a space line satisfying:

[0026]

[0027] where k1, k2, b1, and b2 are parameters of the space - line equation and satisfy:

[0028] 3 - 2) Solve for the equation parameters k1, k2, b1, and b2 by calculating the sum of the squares of the residuals and minimizing it, that is:

[0029]

[0030] 3 - 3) Fit the normal vector of the line, which is the normal vector of the axis direction of the actual engine (6); and perform unit - vectorization of the vector, as:

[0031] The said step 4) includes the following steps:

[0032] Solve for the angle of the robot - end pressing tool in the robot coordinate system according to the target vector;

[0033] 4 - 1) Use the preset initial guess value, tolerance error, maximum number of iterations, and the normal vector of the axis direction as the initial input; extract the direction vector and decompose it into three components;

[0034] 4 - 2) Enter the Newton - iteration loop, calculate the current error, judge the convergence, calculate the Jacobian matrix in turn, and finally update the angle estimate;

[0035] 4 - 3) Convert the radian result to an angle, and feedback the output angle to the robot to make it control the pressing tool to perform non - shaping pressing operation along the axial direction of the engine.

[0036] In step 4 - 1), the set initial guess radian: ABC0 = [0.05, 0.05, 0.05] T ; Define the convergence threshold: e = 10 -8 ; Define the maximum number of iterations: N max = 100.

[0037] Step 4-2) is specifically as follows:

[0038] a. Extract the current radian estimate:

[0039] A = ABC0[1], B = ABC0[2], C = ABC0[3]

[0040] b. Calculate the rotation matrix error function:

[0041]

[0042] c. If the error norm satisfies: Then converge and exit, stopping the iterative loop;

[0043] d. Calculate the Jacobian matrix:

[0044]

[0045] Update the angle estimate:

[0046] ABC = ABC0 - J * f

[0047] where J * represents the matrix pseudo-inverse;

[0048] f. Update the iterative variable: ABC0 = ABC.

[0049] An axial positioning system for an adaptive axial positioning method of a solid rocket motor non-shaping press-fitting tool, comprising:

[0050] The measurement component is: a laser range finder mounted on a robot, the laser range finder is arranged on a linear motion module, and is used to establish a measurement tool coordinate system and perform equidistant sampling on multiple radial sections of the engine to obtain a sampling point coordinate vector;

[0051] An ellipse fitting module, connected to the measurement component, is used to fit the sampling points of each radial section with an ellipse equation to calculate the center coordinates of the ellipse of each section;

[0052] A linear fitting module, connected to the ellipse fitting module, uses the least square method to linearly fit all the center coordinates of the ellipses to generate the engine axis parameters and calculate the corresponding unit vectors;

[0053] The drive control module includes: a linear motion module, a press-fitting tool and a robot, and is used to drive the laser range finder through the linear motion module to perform three-dimensional scanning on the outer surface of the engine. At the same time, based on the Newton iteration method, the attitude of the robot end is calculated to make the axis of the press-fitting tool coincide with the unit vector, and the press-fitting tool is controlled to perform a downward pressing motion along the engine axis direction.

[0054] The present invention has the following beneficial effects and advantages:

[0055] 1. By using the multi-section ellipse fitting and linear regression method, the present invention automatically extracts the actual axial parameters of the fixed engine, overcoming the problem of the deviation of the pressing direction caused by the large aspect ratio and pose deviation in the traditional method. Compared with the passive adjustment of manually calibrating one by one or fixing the pose, this method can dynamically correct the axial deviation, significantly improving the coincidence accuracy between the direction of the pressing tool and the engine axis, and improving the forming quality of the non-shaping process.

[0056] 2. By using the Newton iteration method, the present invention calculates the Euler angles of the end tool of the robot in real time, ensuring that the tool posture quickly converges and aligns with the unit vector of the engine axis. Compared with the traditional trial-and-error method or fixed path planning, this method greatly shortens the adjustment time and avoids the risk of damage to the drug surface caused by repeated adjustments.

[0057] 3. The present invention combines the non-shaping pressing and the active axial positioning of the robot to directly form complex drug profiles without the traditional tool shaping link, eliminating the irreversible damage and safety risks of the shaping process to the processed drug profiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 Flow diagram of the present invention;

[0059] Figure 2 Schematic diagram of the axial positioning error of the non-shaping pressing of the present invention;

[0060] Figure 3 Flow chart of the implementation method of the present invention;

[0061] Figure 4 Structural diagram of the method implementation device of the present invention;

[0062] Figure 5 Effect diagram after the self-adaptive axial positioning of the non-shaping pressing tool of the present invention;

[0063] Wherein: 1 is a robot, 2 is a pressing tool, 3 is a linear motion module, 4 is a laser distance sensor, 5 is a non-shaping tooling, 6 is an engine, 7 is an engine fixing seat, and 8 is the workshop floor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] The following further describes the present invention in detail with reference to the drawings and embodiments.

[0065] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail below with reference to the drawings and specific implementation methods.

[0066] As Figure 1As shown in the figure, it is a schematic flow chart of the present invention. The present invention provides a method for self-adaptive axial positioning of a solid rocket engine non-shaping press-fitting tool, including the following steps:

[0067] Step 1. Establish a measurement tool coordinate system and obtain the coordinate vector of the sampling points on the longitudinal section of the engine;

[0068] Step 2. Fit the ellipse equation of the longitudinal section of the engine for the sampling points to obtain the coordinates of the ellipse center;

[0069] Step 3. Linearly fit the ellipse centers of each radial section to obtain the unit vector of the fitting line;

[0070] Step 4. The robot is adjusted to the height position and performs non-shaping press-fitting operation along the direction of the self-adaptive vector.

[0071] Example 1:

[0072] Specifically, the present invention takes a solid rocket engine as the object:

[0073] As Figure 4 shown, it is the structural diagram of the method implementation device of the present invention. The axial positioning system of a method for self-adaptive axial positioning of a solid rocket engine non-shaping press-fitting tool in this embodiment includes:

[0074] The measurement component is: a laser ranging sensor 4 mounted on the robot 1. The laser ranging sensor 4 is arranged on the linear motion module 3 and is used to establish a measurement tool coordinate system and perform equidistant sampling on multiple radial sections of the engine to obtain the coordinate vector of the sampling points;

[0075] The ellipse fitting module, connected to the measurement component, is used to fit the ellipse equation for the sampling points of each radial section and calculate the coordinates of the ellipse center of each section;

[0076] The linear fitting module, connected to the ellipse fitting module, linearly fits all the ellipse center coordinates by using the least square method, generates the engine axis parameters and calculates the corresponding unit vector;

[0077] The drive control module includes: a linear motion module 3, a press-fitting tool 2 and a robot 1, and is used to drive the laser ranging sensor 4 to perform three-dimensional scanning on the outer surface of the engine through the linear motion module 3. At the same time, based on the Newton iteration method, the end attitude of the robot 1 is calculated to make the axis of the press-fitting tool 2 coincide with the unit vector, and control the press-fitting tool 2 to perform a downward pressing movement along the axis direction of the engine 1.

[0078] Among them, the object to be detected is a solid rocket engine. The engine 6 is fixed on the engine fixing base 7, and the engine fixing base 7 is installed on the horizontal workshop floor 8. The non-shaping tooling 5 is arranged on the engine 6 to cooperate with the pressing tool 2 to ensure the smoothness of the downward pressing process of the robot 1.

[0079] The specific method of this embodiment is as follows:

[0080] Step1: Establish a measuring tool coordinate system and obtain the coordinate vector of the sampling points on the longitudinal section of the engine;

[0081] As Figure 2 shown, there is a deviation between the ideal pose and the actual pose of the engine 6, resulting in a certain angle between the axis of the engine 6 and the ideal axis. In order to adapt to the real pose of each engine 6, it is necessary to measure its corresponding axis parameters. First, establishing the measuring tool coordinate system refers to the coordinate system where the robot 1 is equipped with the laser ranging sensor 4. The coordinate data of the sampling points on the radial section are measured by the laser ranging sensor. The measuring section is γ j , the section height is Z1, the sampling point is P ij , and the sampling point coordinates are (X ij , Y ij ). Each radial section needs to sample at least 6 points. After each radial section sampling is completed, the linear motion module 3 of the laser ranging sensor needs to be adjusted to move a fixed distance h along the Z-axis for the sampling of the next radial section γ j+1 . Sampling is carried out until j = m, Z = Z m , that is, all sampling is completed. The sampling points of each section are defined as a column vector, and these sampling point parameters will be used for the fitting of the section equation. The process is as shown in the Step1 part of Figure 3 .

[0082]

[0083] Among them, Z m is the upper limit of the sampling radial section height, Z1 is the upper limit of the sampling radial section height, and m is the number of sampling radial sections.

[0084] Step2: Fit the ellipse equation of the longitudinal section of the engine for the sampling points to obtain the ellipse center coordinates;

[0085] As Figure 2 shown, due to the axial deviation, the radial section of the actual solid rocket engine is an ellipse. By fitting the ellipse equation for the sampling points of each radial section. The ellipse center coordinates are defined as O j , and the specific parameters are (X 0j , Y 0j , Z j ). By fitting the ellipse equations of each section, the ellipse center coordinates of m are obtained. The process is as shown inFigure 3 as shown in Step 2

[0086] For the ellipse in the radial section, it satisfies:

[0087] Ax 2 +Bxy+Cy 2 +Dx+Ey+F = 0

[0088] where A, B, C, D, E, and F are all constants.

[0089] By substituting the coordinates of the sampling points in the radial section, the center coordinates of the ellipse can be calculated as

[0090]

[0091] Step 3: Linearly fit the centers of the ellipses in each radial section to obtain the unit vector of the fitted straight line;

[0092] As Figure 2 shown, since there are many sampling sections, in order to more accurately reflect the axial parameters of the engine 6, linearly fit the center coordinates of each section. Then, based on the straight line equation after fitting, calculate the unit vector corresponding to the axis of the engine 6.

[0093] Linearly fit all the ellipse centers by the least squares method to obtain the unit vector in the axial direction of the engine 6. The process is as Figure 3 shown in Step 3.

[0094] For a space straight line that satisfies

[0095]

[0096] This formula can be converted into the following form:

[0097]

[0098] where

[0099] By calculating the sum of the squares of the residuals and making it minimum

[0100]

[0101] The equation parameters k1, k2, b1, and b2 can be solved by the above method

[0102]

[0103] At this time, the normal vector of the fitted straight line can be expressed, that is, the normal vector in the direction of the axis of the actual engine 6.

[0104] And further normalize the vector.

[0105]

[0106] Step 4: The robot is adjusted to the height position and performs a non-shaping press-fitting operation along the adaptive vector direction.

[0107] Through the calculations of the foregoing steps, the axial direction vector of the actual engine 6 is obtained, which provides a direction for the robot 1 to control the press-fitting tool 2 to press down the non-shaping tooling 5. Before that, the press-fitting tool 2 needs to be adjusted to the standby position at the top of the engine 6. After the robot 1 is adjusted to the press-fitting height, the angle of the press-fitting tool is calculated by the Newton iteration method to make it coincide with the unit vector, so as to ensure that the press-fitting direction coincides with the axial direction of the actual engine 6. The process is as Figure 3 shown in the Step 4 part. The specific effect after axial positioning is as Figure 5 shown.

[0108] The Newton iteration method aims to solve the angle of the press-fitting tool 2 at the end of the robot 1 in the robot coordinate system according to the target vector. The initial input is set by presetting the initial guess value, tolerance error, maximum number of iterations, and the normal vector of the axis direction; the direction vector is extracted and decomposed into three components; enter the Newton iteration loop, calculate the current error, judge the convergence, calculate the Jacobian matrix in turn, and finally update the angle estimate. When the error is less than the tolerance error, the radian result can be output; finally, the radian result is converted into an angle. The output angle will be fed back to the robot 1 to make it control the press-fitting tool to perform a non-shaping press-fitting operation along the axial direction of the engine. The specific algorithm steps are as follows:

[0109] Input: Target direction vector v = [m, n, k] T , where m 2 +n 2 +k 2 = 1;

[0110] Output: Euler angles A, B, C (unit: °);

[0111] 1: Initialize parameters:

[0112] Set the initial guess radian: ABC0 = [0.05, 0.05, 0.05] T (rad);

[0113] Define the convergence threshold: e = 10 -8 ;

[0114] Define the maximum number of iterations: N max = 100;

[0115] 2: Newton iteration process:

[0116] a. Extract the current angle estimate:

[0117] A = ABC0[1], B = ABC0[2], C = ABC0[3]

[0118] b. Calculate the rotation matrix error function:

[0119]

[0120] c. If the error norm satisfies then converge and exit;

[0121] d. Calculate the Jacobian matrix:

[0122]

[0123] e. Update the radian estimate (pseudo-inverse method):

[0124] ABC = ABC0 - J * f (where J * represents the matrix pseudo-inverse)

[0125] f. Update the iteration variable:

[0126] ABC0 = ABC

[0127] 3: Result output:

[0128] If the number of times t = N max : Display a warning "Reached the maximum number of iterations"

[0129] Convert radians to degrees, that is:

[0130]

[0131] Finally, the output angle is fed back to the robot to enable it to control the press-fitting tool to perform non-shaping press-fitting operations along the axial direction of the engine.

[0132] For the device involved in the implementation method, it is mainly aimed at the non-shaping press-fitting process of the robot for solid rocket engines. Since the introduction of robot kinematics is already very detailed, this description only introduces the adaptive axial positioning method of the non-shaping tool.

[0133] Those skilled in the art can understand that the above is only the preferred embodiment of the present invention. The features described in each embodiment and / or claim of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recorded in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0134] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An adaptive axial positioning method for a solid rocket motor's non-shaping press-fitting tool, characterized in that It includes the following steps: 1) Physical data acquisition: Use a laser range finder rigidly connected to the end of the robot to perform three-dimensional scanning on the outer surface of the engine, and obtain circumferential point cloud data of at least 6 radial cross-sections at equal intervals along the axis; 2) Geometric parameter calculation: Perform ellipse equation fitting on the point cloud of each cross-section in the robot control module, and solve the coordinates of the center of each ellipse; 3) Space axis generation: Linearly fit all ellipse centers by the least squares method to obtain the unit vector in the engine axis direction; 4) Axial press-fitting execution: The robot is adjusted to the press-fitting height, calculate the press-fitting tool angle by the Newton iteration method to make it coincide with the unit vector, and perform a non-shaping press-fitting operation along the vector direction.

2. The self - adaptive axial positioning method of a solid rocket motor's non - shaped press - fitting tool according to claim 1, characterized in that In step 1), the laser range finder is rigidly connected through the flange at the end of the robot. During scanning, the end effector of the robot moves along the engine axis at a preset speed and rotates and scans around the Z axis of the tool coordinate system.

3. An adaptive axial positioning method for a solid rocket motor non-shaping press-fitting tool according to claim 1, characterized in that Step 1) is specifically: 1-1) Establish a measurement tool coordinate system, which refers to the coordinate system where the robot carries the laser range finder, and measure the coordinate data of the sampling points of the radial cross-section through the laser range finder; (1-2) Let the measurement section be γ j , the section height be Z1, and the sampling point be P ij , and the coordinates of the sampling point be (X ij , Y ij ). Each radial section needs to sample at least 6 points; after each radial section is sampled, adjust the linear motion module of the laser distance sensor to move a fixed distance h along the Z-axis for sampling of the next radial section γ j+1 , until j = m, Z = Z m , that is, all sampling is completed; 1-3) Define the sampling points of each cross-section as a column vector for fitting the cross-section equation.

4. A method for adaptive axial positioning of a solid rocket motor non-shaping press-fitting tool according to claim 1, characterized in that In step 1-2), the fixed distance h is: Among them, Z m is the upper limit of the sampling radial section height, Z1 is the upper limit of the sampling radial section height, and m is the number of sampling radial sections.

5. The self - adaptive axial positioning method of the solid rocket motor's non - shaped press - fitting tool according to claim 1, characterized in that Step 2) includes the following steps: 2-1) Perform noise filtering on the point cloud data; and define the center coordinates of the ellipse as O j , with specific parameters (X 0j , Y 0j , Z j ); By fitting the ellipse equations of each cross-section, obtain the center coordinates of m ellipses. 2-2) For the ellipse of the radial cross-section satisfying the equation, that is: Ax 2 +Bxy + Cy 2 +Dx + Ey + F = 0 where A, B, C, D, E, F are all constants; Substitute the coordinates of the sampling points in the radial section, and the center coordinates of the ellipse can be calculated as follows:

6. A method for self - adaptive axial positioning of a solid rocket engine non - shaped press - fitting tool according to claim 1, characterized in that Step 3) includes the following steps: 3-1) For the space straight line satisfying: where k1, k2, b1, and b2 are parameters of the space straight line equation and satisfy: 3-2) Solve the equation parameters k1, k2, b1, b2 by calculating the sum of the squares of the residuals and making it minimum, that is: 3-3) The normal vector of the fitted straight line, which is the normal vector of the axis direction of the actual engine (6); and perform the unitization of the vector, which is:

7. An adaptive axial positioning method for a solid rocket motor's non-shaping press-fitting tool according to claim 1, characterized in that Step 4) includes the following steps: Solve the angle of the press-fitting tool at the end of the robot in the robot coordinate system according to the target vector; 4-1) Use the preset initial guess value, tolerance error, maximum number of iterations, and the normal vector in the axis direction as the initial input; extract the direction vector and decompose it into three components; 4-2) Enter the Newton iteration loop, calculate the current error, judge the convergence, calculate the Jacobian matrix in turn, and finally update the angle estimate; 4-3) Convert the radian result to an angle, and feedback the output angle to the robot to make it control the press-fitting tool to perform a non-shaping press-fitting operation along the engine axis direction.

8. A method for self - adaptive axial positioning of a solid rocket motor's non - shaped press - fitting tool according to claim 7, characterized in that In step 4-1), set the initial guess radian: ABC0 = [0.05, 0.05, 0.05] T ; Define the convergence threshold: e = 10 -8 ; Define the maximum number of iterations: N max = 100.

9. An adaptive axial positioning method for a solid rocket motor non-shaping press-fitting tool according to claim 7, characterized in that Step 4-2) is specifically: a. Extract the current angle estimate: A = ABC0[1], B = ABC0[2], C = ABC0[3] b. Calculate the rotation matrix error function: c. If the error norm satisfies: then converge and exit; d. Calculate the Jacobian matrix: J＝ e. Update the radian estimate: ABC = ABC0 - J * f Among them, J * represents the matrix pseudo-inverse; f. Update the iteration variable: ABC0 = ABC.

10. An axial positioning system for an adaptive axial positioning method of a solid rocket motor non-shaping press-fitting tool according to any one of claims 1 to 9, characterized in that, It includes: The measurement component is: a laser range finder carried on the robot. The laser range finder is arranged on the linear motion module, and is used to establish a measurement tool coordinate system and perform equidistant sampling on multiple radial cross-sections of the engine to obtain the sampling point coordinate vector; The ellipse fitting module is connected to the measurement component and is used to perform ellipse equation fitting on the sampling points of each radial cross-section and calculate the coordinates of the center of the ellipse of each cross-section; A linear fitting module, connected to the ellipse fitting module, uses the least squares method to perform linear fitting on the center coordinates of all ellipses, generates engine axis parameters and calculates the corresponding unit vectors; A drive control module, including: a linear motion module, a pressing tool and a robot, is used to drive a laser range finder to perform three-dimensional scanning on the outer surface of the engine through the linear motion module. At the same time, based on the Newton iteration method, the attitude of the robot end is calculated to make the axis of the pressing tool coincide with the unit vector, and the pressing tool is controlled to perform a downward movement along the engine axis direction.

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