A method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking

Abstract

The present invention discloses a method for precise measurement of micro-postures of aero-engine fuel adjustment spline docking, comprising: establishing an external spline shaft coordinate system, an internal spline hole coordinate system, and a motion reference coordinate system; establishing a theoretical model of chamfer feature constraint space and step-by-step reciprocating scanning data based on spline information; performing a step-by-step reciprocating scanning motion based on axial force perception to obtain scanning data; analyzing and processing the scanning data, combining the theoretical model, fitting the scanning data using the least squares method, determining the data fitting equation and equation coefficients, calculating the micro-posture, and completing precise measurement of the micro-posture. The present invention can achieve precise measurement of micro-postures of aero-engine fuel adjustment spline docking through one-dimensional axial force perception and a specific scanning motion mode, and is also applicable to precise measurement of micro-postures of other cylindrical shaft-hole dockings with C-shaped chamfer features, eliminating dependence on six-dimensional force information, reducing hardware requirements, and improving the accuracy of docking posture measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine component docking posture measurement technology, and in particular to a method for precisely measuring the micro-posture of an aero-engine fuel adjustment spline docking. Background Art

[0002] The aircraft engine fuel pump regulator (hereinafter referred to as the "fuel regulator") is a critical accessory for aircraft engines. During aircraft repair or maintenance, the fuel regulator needs to be disassembled for maintenance and reinstalled for docking. The complex spline structure and numerous installation constraints are the primary docking feature between the aircraft engine fuel regulator and the aircraft engine. Furthermore, due to factors such as the heavy weight and limited installation space of the aircraft engine fuel regulator, measuring the spatial position between the external spline shaft of the aircraft engine fuel regulator and the internal spline hole at the aircraft engine interface during docking is difficult, especially requiring high-precision micro-position measurement.

[0003] In existing aero-engine component docking solutions, docking posture measurement mainly relies on visual sensors or laser ranging sensors to perform preliminary posture measurement, and then adjust the alignment to reduce the posture difference between the shaft and hole to a small range. In the subsequent posture precision adjustment stage, the six-dimensional force sensor installed on the robot wrist or the component fixing fixture is mainly used to obtain six-dimensional force information to make direction judgments and guide adjustments for tiny postures. In the task of docking aero-engine fuel adjustment, the aero-engine fuel adjustment itself is large in size and weight, and the contact force point between the outer spline shaft and the inner spline hole is far away from the force sensor on the fixing fixture, making it impossible to obtain accurate torque information for posture direction judgment and guide adjustments. Therefore, the existing aero-engine component docking solution cannot effectively measure the tiny postures of the aero-engine fuel adjustment spline docking. Summary of the Invention

[0004] 1. Technical problems to be solved:

[0005] In the existing aero-engine component docking scheme, how to effectively measure the micro-posture of the aero-engine fuel adjustment spline docking?

[0006] 2. Technical solution:

[0007] In order to solve the above problems, the present invention provides a method for precisely measuring the micro-posture of the fuel adjustment spline joint of an aircraft engine. The external spline shaft and the internal spline hole are involute splines with an angle of , width is The C-chamfer feature includes the following steps:

[0008] Step S01: In the task of connecting the fuel adjustment spline of an aircraft engine with a micro-posture q, an outer spline shaft coordinate system is established at the center of the top plane of the outer spline shaft, and an inner spline hole coordinate system is established at the center of the top plane of the inner spline hole; the motion reference coordinate system is established in the initial state with reference to the spatial posture of the outer spline shaft coordinate system and coincides with it; the micro-posture q is defined as the vector group , the intermediate variable t is a column vector , represents the spatial position translation of the internal spline hole coordinate system relative to the motion reference coordinate system; the intermediate variable is a column vector , which represents the spatial attitude rotation angle of the internal spline hole coordinate system relative to the motion reference coordinate system.

[0009] Step S02: Based on the spline information, a theoretical model equation of the chamfer feature constraint space and the step-by-step reciprocating scanning trajectory is established.

[0010] Step S03: In the motion reference coordinate system, perform a step-by-step reciprocating scanning motion based on axial force sensing to acquire scanning data.

[0011] Step S04: Analyze and process the scan data, use the least squares method to fit the scan data, determine the data fitting equation and equation coefficients, calculate the micro-pose q, and complete the micro-pose precision measurement task.

[0012] Furthermore, the chamfer feature constraint space is in the process of docking the external spline shaft and the external spline hole, through the geometric constraint and guidance of the chamfer feature, when the two parts are in contact, the origin of the external spline hole coordinate system is The range of motion is limited, and the space constraint area formed has an overall shape of a spatial cone; the cylindrical shaft hole with C-shaped chamfer features can form a chamfer constraint space with a similar shape.

[0013] Furthermore, in step S02, the theoretical model equation of the chamfer feature constraint space of the spline part is:

[0014] ,

[0015] Will Expand this quadratic equation into standard form:

[0016] ,

[0017] Theoretical model equation of chamfer feature constraint space Describes the conical constraint space boundary constructed by the chamfer feature constraint; intermediate variable 、 and The origin of the external spline shaft coordinate system Three-axis coordinate values ​​in the motion reference coordinate system; intermediate variables is the pitch circle radius of the external spline shaft;

[0018] Intermediate variables 、 、 、 、 and h are defined as follows:

[0019] ,

[0020] Intermediate variables and is the shaft hole shape correction coefficient, intermediate variable is the spline shaft hole fit clearance, and ; Intermediate variables A, B, C, D, E, F, G, H, I, J are The variable coefficients of the standard form quadratic equation are expressed by The theoretical model equations are expanded to obtain the variables The constructed function.

[0021] Furthermore, the theoretical model of the step-by-step scanning data is given by the equation and The composition is specifically:

[0022] .

[0023] Furthermore, in step S03, the step-by-step reciprocating scanning motion based on axial force sensing is composed of two groups of scanning motions, namely, the X-axis scanning motion and the Y-axis scanning motion; in the motion reference coordinate system, the origin of the spline axis coordinate system outside the X-axis scanning motion is As the control point, in the XOZ plane of the motion reference coordinate system, the point Start to execute the step-by-step reciprocating scanning motion; the Y-axis scanning motion starts from point Start the step-by-step scanning motion.

[0024] Furthermore, the origin of the spline axis coordinate system outside the X-axis scanning motion As the control point, in the XOZ plane of the motion reference coordinate system, the point Start the scanning motion, specifically: define the total step distance of the step-by-step reciprocating scanning motion in the X-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is ; External spline shaft from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the X-axis , arrive at the second starting point , this process is called an X-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and X-axis stepping motion until the total stepping distance in the positive direction of the X-axis is , get the nth scan data point After that, the X-axis scanning motion is completed and the X-axis scanning data point set is obtained. .

[0025] Furthermore, the origin of the spline axis coordinate system outside the Y-axis scanning motion As the control point, in the YOZ plane of the motion reference coordinate system, the point Start the scanning motion, specifically: define the total step distance of the step-by-step reciprocating scanning motion in the Y-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is ; External spline shaft from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the Y axis. , arrive at the second starting point , this process is called a Y-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and Y-axis stepping motion until the total stepping distance in the positive direction of the Y axis is , get the nth scan data point After that, the Y-axis scanning motion is completed and the Y-axis scanning data point set is obtained. .

[0026] Furthermore, the aircraft engine fuel adjustment docking equipment includes a parallel robot, an electric three-dimensional translation stage, and a fixed fixture with force sensing function; based on the step-by-step reciprocating scanning motion of axial force sensing, the aircraft engine fuel adjustment motion is driven by the electric three-dimensional translation stage, and the axial force on the external spline shaft is monitored by the force sensor on the fixed fixture. .

[0027] Furthermore, after completing the X-axis scanning motion and the Y-axis scanning motion, the origin of the external spline shaft coordinate system Return to the origin of the motion reference coordinate system Position; the condition for contact between the outer spline hole and the inner spline hole is that the outer spline shaft is subjected to an axial force Greater than the set threshold .

[0028] Furthermore, in step S04, the specific method of analyzing and processing the scan data is as follows: scanning the data point set on the X axis Search for the corresponding point of the maximum value of the Z axis , then extract the X-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the X-axis scanning data Fit the data points and solve the values ​​of coefficients A, C, E, G, I, and J; scan the data point set on the Y axis Search for the corresponding point of the maximum value of the Z axis , then extract the Y-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the Y-axis scanning data Fit the data points and solve the values ​​of coefficients B, F, and H; according to the values ​​of coefficients A, B, C, E, F, G, H, I, and J, and the above coefficients are all determined by variables The function is constructed to establish a system of equations to solve the variables , get the micro pose The measured value.

[0029] 3.Beneficial effects:

[0030] The present invention only requires one-dimensional axial force perception combined with a specific scanning motion mode to achieve precise measurement of the micro-posture of the aircraft engine fuel adjustment spline, eliminating the dependence on multi-dimensional force and torque information and reducing hardware requirements; at the same time, it is also suitable for precise measurement of the micro-posture of other cylindrical shaft-hole dockings with C-shaped chamfer features, and has a wide range of applications; compared with traditional solutions that can only perform qualitative directional judgment of the micro-posture of shaft-hole docking, the present invention can quantitatively measure the micro-posture during shaft-hole docking and achieve precise posture measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a method for precise measurement of micro-postures of aero-engine fuel adjustment spline docking provided by the present invention.

[0032] Figure 2 It is a schematic diagram of the coordinate system adopted in the present invention.

[0033] Figure 3 It is a structural composition diagram of the aviation engine fuel adjustment docking equipment provided by the present invention.

[0034] Figure 4 It is a schematic cross-sectional diagram of the X-axis scanning motion adopted by the present invention.

[0035] Figure 5 It is a schematic cross-sectional diagram of the Y-axis scanning motion adopted by the present invention.

[0036] Explanation of the accompanying symbols: 1. Parallel robot; 2. Electric three-dimensional translation stage; 3. Fixing fixture; 4. Aircraft engine fuel adjustment. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] like Figure 1 As shown in the figure, a method for precise measurement of micro-posture of the fuel adjustment spline joint of an aircraft engine is provided. The external spline shaft and the internal spline hole are involute splines with an angle of , width is The C-chamfer feature includes the following steps:

[0039] Step S01:

[0040] In the task of connecting the fuel adjustment spline of an aircraft engine with a micro-posture q, the outer spline shaft coordinate system {P} is established at the center of the top plane of the outer spline shaft, and the inner spline hole coordinate system {H} is established at the center of the top plane of the inner spline hole; the motion reference coordinate system {M} is established with reference to the spatial posture of the outer spline shaft coordinate system {P} in the initial state and coincides with it; the micro-posture q is defined as the vector group , the intermediate variable t is a column vector , represents the spatial position translation of the internal spline hole coordinate system {H} relative to the motion reference coordinate system {M}; the intermediate variable is a column vector , which represents the spatial attitude rotation angle of the internal spline hole coordinate system {H} relative to the motion reference coordinate system {M}.

[0041] Step S02: Based on the spline information, a theoretical model equation of the chamfer feature constraint space and the step-by-step reciprocating scanning trajectory is established.

[0042] Step S03: In the motion reference coordinate system {M}, a step-by-step reciprocating scanning motion based on axial force sensing is performed to acquire scanning data.

[0043] Step S04: Analyze and process the scan data, use the least squares method to fit the scan data, determine the data fitting equation and equation coefficients, calculate the micro-pose q, and complete the micro-pose precision measurement task.

[0044] In step S01, the aero-engine fuel adjustment spline docking task with a micro posture q is a task of precisely measuring the existing micro posture q after completing the tooth alignment and preliminary posture alignment; Figure 2 As shown, the external spline shaft coordinate system {P} is established at the center of the top plane of the external spline shaft, and the internal spline hole coordinate system {H} is established at the center of the top plane of the internal spline hole; the motion reference coordinate system {M} is established in the initial state with reference to the spatial posture of the external spline shaft coordinate system {P} and coincides with it.

[0045] The micro pose q is defined as the vector set , the intermediate variable t is a column vector , represents the spatial position translation of the internal spline hole coordinate system {H} relative to the motion reference coordinate system {M}, where a is the translation along the X axis, b is the translation along the Y axis, and c is the translation along the Z axis, and the value range is 、 and ; Intermediate variables is a column vector , represents the spatial attitude rotation angle of the internal spline hole coordinate system {H} relative to the motion reference coordinate system {M}, where is the rotation angle around the X axis, is the rotation angle around the Y axis, and its value range is 、 .

[0046] Step S02, in one embodiment, the spline size information is: the external spline shaft part of the aircraft engine fuel adjustment and the internal spline hole part of the docking target are involute splines with an angle of , width is C-shaped chamfer feature, and ;The clearance between the spline shaft and the hole is ,and , the pitch circle radius of the external spline shaft is ,and .

[0047] The chamfer feature constraint space is the process of connecting the external spline shaft and the external spline hole. Through the geometric constraint and guidance of the chamfer feature, when the two parts are in contact, the origin of the external spline hole coordinate system is The range of motion is limited, and the space constraint area formed has an overall shape of a spatial cone. According to the known spline size information, in one embodiment, the theoretical model equation for the chamfer feature constraint space is established as follows:

[0048] .

[0049] Will Expand this quadratic equation into standard form:

[0050] .

[0051] Theoretical model equation of chamfer feature constraint space Describes the conical constraint space boundary constructed by the chamfer feature constraint; among them, the intermediate variable 、 and The origin of the external spline shaft coordinate system Three-axis coordinate values ​​in the motion reference coordinate system {M}; intermediate variables 、 、 、 、 and h are defined as follows:

[0052] ,

[0053] Intermediate variables and is the shaft hole shape correction coefficient; for the spline part docking task in this embodiment, the intermediate variable The value range is , intermediate variables .

[0054] The intermediate variables A, B, C, D, E, F, G, H, I, and J are The variable coefficients of the standard form quadratic equation are expressed by The theoretical model equations are expanded to obtain the variables The constructed function.

[0055] In one embodiment, the step-by-step reciprocating scanning data is created and The theoretical model equation is:

[0056] .

[0057] Step S03: Figure 3 As shown, the aircraft engine fuel adjustment docking equipment consists of a parallel robot 1, an electric three-dimensional translation stage 2, and a fixed fixture 3 with force sensing function. Based on the step-by-step reciprocating scanning motion of axial force sensing, the electric three-dimensional translation stage 2 drives the aircraft engine fuel adjustment 4 to move, and the force sensor on the fixed fixture 3 monitors the axial force on the external spline shaft. ; The step-by-step reciprocating scanning motion based on axial force sensing consists of two groups of scanning motions, namely X-axis scanning motion and Y-axis scanning motion.

[0058] The X-axis scanning motion works in the XOZ plane of the motion reference coordinate system {M}, and the electric three-dimensional translation stage 2 drives the aircraft engine fuel adjustment 4 to move so that the origin of the external spline shaft coordinate system , in the XOZ plane from point Start the scanning motion. Define the total stepping distance of the step-by-step reciprocating scanning motion in the X-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is .

[0059] like Figure 4 As shown, the external spline shaft starts from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the X-axis , arrive at the second starting point , this process is called an X-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and X-axis stepping motion until the total stepping distance in the positive direction of the X-axis is , get the nth scan data point After that, the X-axis scanning motion is completed and the X-axis scanning data point set is obtained. .

[0060] The Y-axis scanning motion works in the YOZ plane of the motion reference coordinate system {M}, and the electric three-dimensional translation stage 2 drives the aircraft engine fuel adjustment 4 to move so that the origin of the external spline shaft coordinate system , in the YOZ plane from point Start the scanning motion. Define the total stepping distance of the step-by-step reciprocating scanning motion in the Y-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is .

[0061] like Figure 5 As shown, the external spline shaft starts from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the Y axis. , arrive at the second starting point , this process is called a Y-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and Y-axis stepping motion until the total stepping distance in the positive direction of the Y axis is , get the nth scan data point After that, the Y-axis scanning motion is completed and the Y-axis scanning data point set is obtained. .

[0062] After completing the X-axis scanning motion and the Y-axis scanning motion, the origin of the external spline shaft coordinate system Return to the origin of the motion reference coordinate system Position; the condition for contact between the outer spline hole and the inner spline hole is that the outer spline shaft is subjected to an axial force Greater than the set threshold ,and .

[0063] Step S04: In one embodiment, the specific steps of analyzing and processing the scanning trajectory are:

[0064] Scan a set of data points along the X axis Search for the corresponding point of the maximum value of the Z axis , then extract the X-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the X-axis scanning data Fit the data points and calculate the values ​​of coefficients A, C, E, G, I, and J.

[0065] Scan a set of data points along the Y axis Search for the corresponding point of the maximum value of the Z axis , then extract the Y-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the Y-axis scanning data Fit the data points and solve the values ​​of coefficients B, F, and H; according to the values ​​of coefficients A, B, C, E, F, G, H, I, and J, and the above coefficients are all determined by variables The function is constructed to establish a system of equations to solve the variables , get the micro pose The measured value.

[0066] According to the measured micro-posture q, the external spline shaft posture is adjusted to complete the micro-posture adjustment.

[0067] The above describes, with reference to the accompanying drawings, an exemplary flow chart for achieving precise measurement of the micro-position of the fuel adjustment spline docking of an aircraft engine according to an embodiment of the present invention. It should be noted that the numerous details included in the above description are merely exemplary illustrations of the present invention and are not intended to limit the present invention. In other embodiments of the present invention, the method may have more, fewer, or different steps, and the order, inclusion, functionality, and other relationships between the steps may differ from those described and illustrated.

Claims

1. A method for precise measurement of micro-posture of the joint of the fuel adjustment spline of an aircraft engine. The external spline shaft and the internal spline hole are involute splines with an angle of , width is The C-type chamfer feature is characterized by: The following steps are involved: Step S01: In the task of connecting the fuel adjustment spline of an aircraft engine with a micro-posture q, an outer spline shaft coordinate system is established at the center of the top plane of the outer spline shaft, and an inner spline hole coordinate system is established at the center of the top plane of the inner spline hole; the motion reference coordinate system is established in the initial state with reference to the spatial posture of the outer spline shaft coordinate system and coincides with it; the micro-posture q is defined as the vector group , the intermediate variable t is a column vector , represents the spatial position translation of the internal spline hole coordinate system relative to the motion reference coordinate system; Intermediate variables is a column vector , represents the spatial attitude rotation angle of the internal spline hole coordinate system relative to the motion reference coordinate system; Step S02: establishing a theoretical model equation of the chamfer feature constraint space and the step-by-step reciprocating scanning trajectory based on the spline information; Step S03: In the motion reference coordinate system, perform a step-by-step reciprocating scanning motion based on axial force sensing to obtain scanning data; in step S03, the step-by-step reciprocating scanning motion based on axial force sensing consists of two groups of scanning motions, namely, X-axis scanning motion and Y-axis scanning motion; in the motion reference coordinate system, the origin of the spline axis coordinate system outside the X-axis scanning motion is As the control point, in the XOZ plane of the motion reference coordinate system, the point Start to execute the step-by-step reciprocating scanning motion; the Y-axis scanning motion starts from point Start to execute the step-by-step reciprocating scanning motion; Step S04: Analyze and process the scan data, use the least squares method to fit the scan data, determine the data fitting equation and equation coefficients, calculate the micro-pose q, and complete the micro-pose precision measurement task; In step S04, the specific method of analyzing and processing the scan data is: scan the data point set on the X axis Search for the corresponding point of the maximum value of the Z axis , then extract the X-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the X-axis scanning data Fit the data points and solve the values ​​of coefficients A, C, E, G, I, and J; scan the data point set on the Y axis Search for the corresponding point of the maximum value of the Z axis , then extract the Y-axis coordinate value in Data points within the range constitute a data point set ; Set the data points The Z axis value is greater than After eliminating the points, the least square method is used, based on the theoretical equation of the Y-axis scanning data Fit the data points and solve the values ​​of coefficients B, F, and H; according to the values ​​of coefficients A, B, C, E, F, G, H, I, and J, and the above coefficients are all determined by variables The function is constructed to establish a system of equations to solve the variables , get the micro pose The measured value of The chamfer feature constraint space is the process of connecting the external spline shaft and the internal spline hole. Through the geometric constraint and guidance of the chamfer feature, when the two parts are in contact, the origin of the external spline shaft coordinate system is The range of motion is limited, and the space constraint area formed has an overall shape of a spatial cone; the cylindrical shaft hole with C-shaped chamfer features can form a chamfer constraint space with a similar shape; The theoretical model equation of the chamfer feature constraint space of spline parts is: ， Will Expand this quadratic equation into standard form: ， Theoretical model equation of chamfer feature constraint space Describes the conical constraint space boundary constructed by the chamfer feature constraint; intermediate variable 、 and The origin of the external spline shaft coordinate system Three-axis coordinate values ​​in the motion reference coordinate system; Intermediate variables is the pitch circle radius of the external spline shaft; Intermediate variables 、 、 、 、 and h are defined as follows: ， Intermediate variables and is the shaft hole shape correction coefficient, intermediate variable is the spline shaft hole fit clearance, and ; The intermediate variables A, B, C, D, E, F, G, H, I, and J are The variable coefficients of the standard form quadratic equation are expressed by The theoretical model equations are expanded to obtain the variables The constructed function.

2. The method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking according to claim 1, characterized in that: The theoretical model of step-and-reciprocate scanning data is given by the equation and The composition is specifically: 。 3. The method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking according to claim 1, characterized in that: The origin of the spline axis coordinate system outside the X-axis scanning motion As the control point, in the XOZ plane of the motion reference coordinate system, the point Start the scanning motion, specifically: define the total step distance of the step-by-step reciprocating scanning motion in the X-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is ; External spline shaft from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the X-axis , arrive at the second starting point , this process is called an X-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and X-axis stepping motion until the total stepping distance in the positive direction of the X-axis is , get the nth scan data point After that, the X-axis scanning motion is completed and the X-axis scanning data point set is obtained. .

4. The method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking according to claim 3, characterized in that: The origin of the spline axis coordinate system outside the Y-axis scanning motion As the control point, in the YOZ plane of the motion reference coordinate system, the point Start the scanning motion, specifically: define the total step distance of the step-by-step reciprocating scanning motion in the Y-axis direction as , the unit step distance is ,and , n is the number of scanning data points to be acquired, and the scanning distance in the Z-axis direction is ; External spline shaft from the first starting point Start and execute the movement distance in the positive direction of Z axis The command is executed until it contacts the inner spline hole or reaches the position specified by the motion command, and stops moving. The coordinates of the first scanning data point are recorded as , then return to point , this process is called a Z-axis reciprocating scanning motion; then the distance is stepped in the positive direction of the Y axis. , arrive at the second starting point , this process is called a Y-axis stepping motion; from the second starting point Start to repeat the above Z-axis reciprocating scanning motion and Y-axis stepping motion until the total stepping distance in the positive direction of the Y axis is , get the nth scan data point After that, the Y-axis scanning motion is completed and the Y-axis scanning data point set is obtained. .

5. The method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking according to claim 4, characterized in that: The aircraft engine fuel adjustment docking equipment includes a parallel robot (1), an electric three-dimensional translation stage (2), and a fixed fixture (3) with a force sensing function; the electric three-dimensional translation stage (2) drives the aircraft engine fuel adjustment (4) to move based on the step-by-step reciprocating scanning motion of the axial force sensing, and the force sensor on the fixed fixture (3) monitors the axial force on the external spline shaft. .

6. The method for precise measurement of micro-posture of aero-engine fuel adjustment spline docking according to claim 5, characterized in that: After completing the X-axis scanning motion and the Y-axis scanning motion, the origin of the external spline shaft coordinate system Return to the origin of the motion reference coordinate system Position; the condition for the contact between the outer spline shaft and the inner spline hole is that the outer spline shaft is subjected to an axial force Greater than the set threshold .

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