Compensation processing method and system for online measurement of window feature of weak-rigid rotary body shell segment

Abstract

A weak rigid rotary shell segment window feature online measurement compensation processing method, including carrying out profile detection, obtaining the deviation value from the normal direction of the theoretical position of the outer surface; calculating the angle compensation value: according to the position of the four measuring points in the local coordinate system and the deviation value, the angle compensation value is calculated; calculating the deviation value of the measuring point after angle compensation: according to the angle compensation value and the position of the measuring point, the deviation value of the eight measuring points after angle compensation is calculated; deviation value detection: according to the deviation value after angle compensation, whether the maximum and minimum value range can meet the tolerance band requirement is calculated, and alarm is given if it exceeds the tolerance band; if it meets the tolerance requirement, the tool length compensation value is calculated; calculating the tool length compensation value: the median value of the deviation value of the measuring point after angle compensation is taken as the tool length compensation value of the processing program; sinking processing. The present application can realize automatic processing of large weak rigid rotary shell segment window features, can replace manual operation and ensure continuous machining of machine tools, and effectively improve the quality stability and processing efficiency of products.

Description

TECHNICAL FIELD

[0001] The present application relates to a weak rigid shell segment window feature online measurement compensation processing method and system, belonging to the technical field of machining. BACKGROUND

[0002] The shape of a large thin-walled shell is generally cylindrical or conical, and the outer diameter is Φ1000-Φ2000mm, as shown in Figs. a and b. The window feature is generally rectangular or elliptical, and the window sag depth tolerance is generally within ±0.2mm, as shown in Fig. c. Figure 1 Figure 2

[0003] The window sag processing procedure is after the shell segment outer shape turning finishing. Since the shell body belongs to a thin-walled weak rigid structure, the roundness deformation of the shell segment after finishing is large, generally about 1.5-2.5mm, and the local deformation of the shell segment product causes the sag depth size to be unable to be guaranteed.

[0004] The window sag is the installation area of the shell segment operation cover, and if the sag depth cannot be guaranteed, it will affect the pneumatic shape after the cover is installed. The window sag is realized by the way of tool shaft perpendicular to the machining surface, i.e. normal machining, and if the window sag depth deviation can meet the tolerance requirement, the tool length parameter can be adjusted to realize the machining.

[0005] The existing processing method needs the operator to pre-process the feature during the processing process, then manually select multiple measurement points to measure the sag depth, and then adjust the tool length parameter for processing to guarantee the depth tolerance. If the shape surface deformation is too large, causing the sag depth to be unable to guarantee the depth, the processing program needs to be modified according to the measurement situation, and then the pre-processing, measurement and other steps are repeated, which has the following problems:

[0006] (1) Too many manual operation links, low efficiency

[0007] The operator needs to measure the depth of the window sag during the processing process, and manually modify the tool length parameter of the numerical control system to realize the processing. If the tolerance cannot be guaranteed, the program needs to be modified by communicating with the programmer, and there are too many manual operation links in the processing process. At the same time, the above operations need to be completed during shutdown, which causes low processing efficiency.

[0008] (2) There is a great quality risk in manual operation

[0009] There are too many manual operation links in the processing process, and the quality guarantee is seriously dependent on the skill level of the operator. Once an error occurs, it will cause irreparable quality loss, which has a great quality risk.

[0010] ​​The above problems severely restrict the processing efficiency and quality assurance of shell products. Therefore, reducing the reliance on manual operation in this feature processing and improving the degree of automation are urgent issues that need to be addressed. Summary of the Invention

[0011] The technical problem solved by this invention is to overcome the shortcomings of the prior art and address the issues of excessive manual operation, low efficiency, and significant quality risks in existing methods for processing window features of weakly rigid rotating shell segments. This invention provides an online measurement and compensation processing method for window features of weakly rigid rotating shell segments, enabling adaptive processing of window features of large, weakly rigid rotating shell segments.

[0012] The technical solution of this invention is:

[0013] A method for online measurement and compensation of window features in a weakly rigid rotating shell segment includes:

[0014] Surface inspection: Determine the location and number of measuring points, use a 3D probe to measure the actual position of the measuring points, and obtain the deviation value δ from the theoretical position of the outer surface in the normal direction. i ;

[0015] Calculate the angle compensation value: Calculate the angle compensation value based on the position and deviation value of the four measuring points in the local coordinate system;

[0016] Calculate the deviation value of the measuring points after angle compensation: Based on the angle compensation value and the position of the measuring points, calculate the deviation value of the 8 measuring points after angle compensation;

[0017] Deviation detection: Based on the deviation value after angle compensation, calculate whether the maximum and minimum value range can meet the tolerance zone requirements. If the deviation value is exceeded, an alarm will be triggered and processing will be paused; if the tolerance requirements are met, the tool length compensation value will continue to be calculated.

[0018] Calculate the tool length compensation value: Based on the deviation value of the measuring point after angle compensation, calculate the midpoint as the tool length compensation value of the machining program;

[0019] Depression machining: Angle compensation values ​​and tool length compensation values ​​are written into the CNC system to achieve adaptive machining of depression depth.

[0020] Furthermore, the selection of measurement points is based on the following principles:

[0021] Rectangular window: The measurement points are selected as the center points of each side of the rectangular concave outline and the four corner points, for a total of 8 points;

[0022] Elliptical window: The measurement points are selected as the four poles of the major axis and minor axis of the elliptical concave contour line, and four points with evenly distributed arc lengths between the poles, for a total of eight points.

[0023] Further, according to the actual position of the measuring point, the deviation value from the normal direction of the theoretical position of the profile surface is obtained, specifically:

[0024] According to the different types of windows, the positions of the eight measuring points are measured in turn by the 3D measuring head;

[0025] The difference between the actual position and the theoretical position of the measuring point in the normal direction of the profile surface is calculated as the deviation value δ i , i = 1, 2,..., 8.

[0026] Further, the reconstruction of the machining trajectory is realized by rotating machining, and the rotating directions are the window generatrix direction and the perpendicular direction of the generatrix, respectively.

[0027] Further, the local coordinate system is defined as:

[0028] Coordinate origin: The coordinate origin is set as the center of symmetry of the operating window, i.e. the center of the rectangular window and the center of the elliptical window;

[0029] Coordinate axis: Among them, the generatrix direction is set as the Y axis, the normal direction of the coordinate origin is set as the Z axis, and the X axis is determined according to the principle of the rectangular coordinate system.

[0030] Further, the angle compensation value is calculated according to the positions and deviation values of the four measuring points in the local coordinate system, specifically:

[0031] Rotating angle compensation value θ x , θ y is calculated by the profile deviation values of points P1-P4,

[0032]

[0033] Among them, δ1-δ4 are the profile deviation values of points P1-P4, Y1, Y3, X2, X4 are the coordinate axis components of points P1-P4 in the local coordinate system.

[0034] Further, the measuring point deviation value after angle compensation is calculated, specifically:

[0035] δ′ i = δ i -X i ·sinθ y +Y i ·sinθ x , i = 1,..., 8

[0036] Among them, δ′ i is the deviation value of each point after angle compensation, X i , Y i is the coordinate axis component of the measuring point in the local coordinate system.

[0037] Further, the median of the angle-compensated measuring point deviation values is calculated as the tool length compensation value of the machining program, specifically:

[0038]

[0039] The tool length compensation value is L t , δ' max , and δ' min are the maximum and minimum angle-compensated deviation values, respectively.

[0040] Further, the present application also proposes a weak-rigidity rotary shell segment window feature online measurement compensation machining system, comprising:

[0041] A profile detection module: determines the measuring point positions and the number of measuring points, uses a 3D probe to measure the actual positions of the measuring points, and obtains the deviation value δ i of the normal direction of the theoretical position of the profile surface.

[0042] The measuring point selection is based on the following principles:

[0043] Rectangular window: the measuring points are selected as the center points of each side of the rectangular sunken contour line and the four corner points, totaling 8 points.

[0044] Elliptical window: the measuring points are selected as the four extreme points of the long axis and the short axis of the elliptical sunken contour line and the four points evenly distributed along the arc between the extreme points, totaling 8 points.

[0045] An angle compensation value calculation module: calculates the angle compensation value based on the positions and deviation values of the four measuring points in the local coordinate system.

[0046] The local coordinate system is defined as:

[0047] Coordinate origin: the coordinate origin is set as the center of symmetry of the operating window, i.e., the center of the rectangular window and the center of the elliptical window.

[0048] Coordinate axes: the generatrix direction is set as the Y-axis, the normal of the surface at the origin is set as the Z-axis, and the X-axis is determined according to the right-angle coordinate system principle.

[0049] An angle-compensated measuring point deviation value calculation module: calculates the deviation values of the eight measuring points after angle compensation based on the angle compensation value and the measuring point positions.

[0050] A deviation value detection module: calculates whether the maximum and minimum values of the angle-compensated deviation values can meet the tolerance band requirements, and if they exceed the tolerance band, an alarm is issued to pause the machining; if they meet the tolerance requirements, the tool length compensation value is calculated.

[0051] A tool length compensation value calculation module: calculates the median of the angle-compensated measuring point deviation values as the tool length compensation value of the machining program.

[0052] Sunken processing module: write angle compensation value and tool length compensation value into numerical control system, realize adaptive processing of sunken depth.

[0053] The beneficial effects of the present application compared with the prior art are:

[0054] (1) The present application can realize automatic processing of window features of large weak rigid rotary shell segments, and automatically reconstruct processing trajectories according to the deformation of the shell segment, realize adaptive processing of accurate feature size control, the method can completely replace manual operation of the operator and ensure continuous processing of the machine tool, effectively improve the quality stability and processing efficiency of the product.

[0055] (2) The method solves the problems of manual operation, low efficiency and large quality hidden trouble of the existing weak rigid rotary shell segment window feature processing method, and can realize adaptive processing of large weak rigid rotary shell segment window features. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 It is a schematic diagram of a typical shell segment of the present application;

[0057] Figure 2 It is a schematic diagram of the window feature of the present application;

[0058] Figure 3 It is a schematic diagram of 3D probe measurement of the present application;

[0059] Figure 4 It is a schematic diagram of the measurement point position of the present application;

[0060] Figure 5 It is a schematic diagram of the profile surface deviation value of the present application;

[0061] Figure 6 It is a schematic diagram of the window processing local coordinate system of the present application;

[0062] Figure 7 It is a schematic diagram of the window local coordinate system setting of the present application;

[0063] Figure 8 It is a window sunken online measurement compensation processing flowchart of the present application. DETAILED DESCRIPTION

[0064] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0065] The present application takes the window feature of a large weak rigid shell segment as the research object, and proposes an online measurement compensation processing method, wherein the online measurement part measures the shape surface deviation of the window sag processing position of the shell segment through a 3D probe to replace the manual depth gauge measurement of the operator; the online compensation part realizes the automatic calculation of the processing track reconstruction and the tool length compensation value through the self-developed compensation calculation algorithm, and finally realizes the adaptive processing of the window feature of the large weak rigid shell segment.

[0066] As shown in Figure 8 , the present application proposes a weak rigid shell segment window feature online measurement compensation processing method, including the following steps:

[0067] (1) Perform surface detection: determine the measurement point position and the number of measurement points, measure the actual position of the measurement points using a 3D probe, and obtain the deviation value δ i from the normal direction of the theoretical position of the shape surface;

[0068] (2) Calculate the angle compensation value: calculate the angle compensation value according to the positions and deviation values of the four measurement points in the local coordinate system;

[0069] (3) Calculate the deviation value of the measurement points after angle compensation: calculate the deviation values of the eight measurement points after angle compensation according to the angle compensation value and the measurement point position;

[0070] (4) Deviation value detection: calculate whether the maximum and minimum value range after angle compensation can meet the tolerance band requirement, and if it exceeds the tolerance band, an alarm is given to suspend processing; if it meets the tolerance requirement, the tool length compensation value is calculated;

[0071] (5) Calculate the tool length compensation value: calculate the median value of the measurement point deviation values after angle compensation as the tool length compensation value of the processing program;

[0072] (6) Sag processing: write the angle compensation value and the tool length compensation value into the numerical control system to realize adaptive processing of the sag depth.

[0073] The present application cancels the rough machining process, measures the sag processing position shape surface using a 3D probe, determines the deviation value of the shape surface to determine the depth deviation value after sag processing, and the measurement process is as shown in Figure 3 .

[0074] To meet the requirements of subsequent compensation functions, the present application selects the measurement points based on the following principles:

[0075] (1) Rectangular window: select the center points of each side of the rectangular sag contour line and the four corner points, a total of eight points, as shown in Figure 4 .

[0076] (2) Elliptical window: The measuring points are selected as the four poles of the major and minor axes of the elliptical contour line, and four points with evenly distributed arc lengths between the poles, for a total of eight points, such as... Figure 4 As shown in b.

[0077] The automatic measurement process for surface deviation is as follows:

[0078] 1) Depending on the window type, the positions of 8 measuring points are measured sequentially using a 3D probe;

[0079] 2) Calculate the deviation δ between the actual position and the theoretical position of the measuring point in the normal direction of the external surface. i (i=1,2,…,8), such as Figure 5 As shown.

[0080] The window recess is typically a ring-shaped machining area of ​​equal width. To compensate for the impact of surface deformation on dimensional accuracy, this invention employs a rotary machining program to reconstruct the machining trajectory. The rotation directions are the window generatrix direction and the direction perpendicular to the generatrix, respectively. Figure 6 As shown.

[0081] The rotation function is implemented using the local coordinate system function in the CNC system, and the principles for setting the local coordinate system are as follows:

[0082] 1) Origin of coordinates: The origin of coordinates is set as the center of symmetry of the operation window, that is, the center of the rectangular window and the center of the elliptical window.

[0083] 2) Coordinate axes: The generatrix direction is set as the Y-axis, the surface normal at the origin is set as the Z-axis, and the X-axis is determined according to the principles of a rectangular coordinate system, such as... Figure 7 As shown.

[0084] To compensate for the deformation of the outer surface, compensation is achieved by adjusting the rotation angles in the X and Y directions of the local coordinate system and the tool length compensation value, where the rotation angle compensation value θ x θ y The deviation values ​​of the shape at points P1 to P4 are calculated as shown in formula (1).

[0085]

[0086] Where δ1~δ4 are the shape deviation values ​​of points P1~P4, and Y1, Y3, X2, X4 are the coordinate axis components of points P1~P4 in the local coordinate system.

[0087] The calculation of the tool length compensation value first requires calculating the deviation between the actual and theoretical positions of each measuring point after angle compensation. The maximum and minimum deviation values ​​are then used to determine if they meet the tolerance requirements. If the tolerance requirements are met, the tool length compensation value is calculated based on the median value. If the tolerance requirements are not met, an alarm is triggered. The deviation value δ′ at each point after angle compensation is specified. iThe calculation of the rotation angle value θ t is shown as formula (2), and the tool length compensation value L is shown as formula (3).

[0088] δ′ i = δ i -X i ·sinθ y +Y i ·sinθ x , i = 1,..., 8 (2)

[0089]

[0090] According to different numerical control systems, the compensation calculation programs of the rotation angle value θ x , θ y and the tool length compensation value L t are programmed through the above algorithms, so that the automatic measurement compensation machining of the window feature can be realized.

[0091] The present application can realize the automatic machining of the window feature of a large weak rigid rotary shell segment, and automatically reconstruct the machining track according to the deformation of the shell segment, realize the self-adaptive machining of the accurate control of the feature size, the method can completely replace the manual operation of the operator and ensure the continuous machining of the machine tool, and effectively improve the quality stability and machining efficiency of the product.

[0092] The part not described in detail in the present application is the common knowledge of the person skilled in the art.

Claims

1. A method for online measurement and compensation of window features in a weakly rigid rotating shell segment, characterized in that... include: Surface inspection: Determine the location and number of measuring points, use a 3D probe to measure the actual position of the measuring points, and obtain the deviation value δ from the theoretical position of the outer surface in the normal direction. i ; Calculate the angle compensation value: Calculate the angle compensation value based on the position and deviation value of the four measuring points in the local coordinate system; Calculate the deviation value of the measuring points after angle compensation: Based on the angle compensation value and the position of the measuring points, calculate the deviation value of the 8 measuring points after angle compensation; Deviation detection: Based on the deviation value after angle compensation, calculate whether the maximum and minimum value range can meet the tolerance zone requirements. If the deviation value is exceeded, an alarm will be triggered and processing will be paused; if the tolerance requirements are met, the tool length compensation value will continue to be calculated. Calculate the tool length compensation value: Based on the deviation value of the measuring point after angle compensation, calculate the midpoint as the tool length compensation value of the machining program; Depression machining: The angle compensation value and tool length compensation value are written into the CNC system to achieve adaptive machining of the depression depth; The angle compensation value is calculated based on the position and deviation of the four measuring points in the local coordinate system, specifically as follows: Rotation angle compensation value θ x θ y Calculated using the shape deviation values ​​of points P1 to P4. Where δ1~δ4 are the shape deviation values ​​of the four poles P1~P4 of the major axis and minor axis, and Y1, Y3, X2, X4 are the coordinate axis components of points P1~P4 in the local coordinate system. The step of calculating the midpoint of the measured point deviation value after angle compensation as the tool length compensation value for the machining program is as follows: Among them, the tool length compensation value is L t ,δ′ max ,δ′ min These are the maximum and minimum deviation values ​​after angle compensation, respectively.

2. The online measurement and compensation processing method for window features of a weakly rigid rotating shell segment according to claim 1, characterized in that: The selection of measuring points is based on the following principles: Rectangular window: The measurement points are selected as the center points of each side of the rectangular concave outline and the four corner points, for a total of 8 points; Elliptical window: The measurement points are selected as the four poles of the major axis and minor axis of the elliptical concave contour line, and four points with evenly distributed arc lengths between the poles, for a total of eight points.

3. The online measurement and compensation processing method for window features of a weakly rigid rotating shell segment according to claim 2, characterized in that: Based on the actual position of the measuring point, the deviation value from the normal direction of the theoretical position of the outer surface is obtained, specifically: Depending on the window type, the positions of 8 measuring points are measured sequentially using a 3D probe; The difference is calculated to determine the deviation δ between the actual and theoretical positions of the measuring point in the direction normal to the external surface. i , i = 1, 2, ..., 8.

4. The online measurement and compensation processing method for window features of a weakly rigid rotating shell segment according to claim 1, characterized in that: The machining trajectory is reconstructed by rotating the machining process in a local coordinate system, with the rotation directions being the window generatrix direction and the generatrix perpendicular direction.

5. The online measurement and compensation processing method for window features of a weakly rigid rotating shell segment according to claim 1, characterized in that: The local coordinate system is defined as follows: Origin of coordinates: The origin of coordinates is set as the center of symmetry of the operation window, that is, the center of the rectangular window and the center of the elliptical window. Coordinate axes: The direction of the generatrix is ​​set as the Y-axis, the surface normal at the origin is set as the Z-axis, and the X-axis is determined according to the principles of the rectangular coordinate system.

6. The online measurement and compensation processing method for window features of a weakly rigid rotating shell segment according to claim 1, characterized in that: The deviation value of the measuring point after angle compensation is calculated as follows: d′ i =d i -X i ·sinθ y +Y i ·sinθ x ,i=1,...,8 Where, δ′ i X represents the deviation value at each point after angle compensation. i Y i These are the coordinate axis components of the measuring point in the local coordinate system.

7. An online measurement and compensation machining system for window features of a weakly rigid rotating shell segment, characterized in that... include: Surface Inspection Module: Determines the location and number of measuring points, uses a 3D probe to measure the actual position of the measuring points, and obtains the deviation value δ from the theoretical position of the outer surface in the normal direction. i ; The selection of measuring points is based on the following principles: Rectangular window: The measurement points are selected as the center points of each side of the rectangular concave outline and the four corner points, for a total of 8 points; Elliptical window: The measurement points are selected as the four poles of the major axis and minor axis of the elliptical concave contour line, and four points with evenly distributed arc lengths between the poles, for a total of eight points; Angle compensation value calculation module: Calculates the angle compensation value based on the position and deviation of 4 measuring points in the local coordinate system; The local coordinate system is defined as follows: Origin of coordinates: The origin of coordinates is set as the center of symmetry of the operation window, that is, the center of the rectangular window and the center of the elliptical window. Coordinate axes: The direction of the generatrix is ​​set as the Y-axis, the normal of the surface at the origin is set as the Z-axis, and the X-axis is determined according to the principles of the rectangular coordinate system; Angle-compensated measurement point deviation calculation module: Calculates the deviation values ​​of the 8 measurement points after angle compensation based on the angle compensation value and the measurement point position; Deviation detection module: Based on the deviation value after angle compensation, calculate whether the maximum and minimum value range can meet the tolerance zone requirements. If it exceeds the tolerance zone, an alarm will be triggered to suspend processing; if the tolerance requirements are met, the tool length compensation value will continue to be calculated. Tool length compensation value calculation module: Calculates the midpoint of the measurement point deviation value after angle compensation as the tool length compensation value of the machining program; Depression machining module: The angle compensation value and tool length compensation value are written into the CNC system to realize adaptive machining of the depression depth; The angle compensation value is calculated based on the position and deviation of the four measuring points in the local coordinate system, specifically as follows: Rotation angle compensation value θ x θ y Calculated using the shape deviation values ​​of points P1 to P4. Where δ1~δ4 are the shape deviation values ​​of the four poles P1~P4 of the major axis and minor axis, and Y1, Y3, X2, X4 are the coordinate axis components of points P1~P4 in the local coordinate system. The deviation value of the measuring point after angle compensation is calculated as follows: d′ i =d i -X i ·sinθ y +Y i ·sinθ x ,i=1,...,8 Where, δ′ i X represents the deviation value at each point after angle compensation. i Y i These are the coordinate axis components of the measuring point in the local coordinate system; The step of calculating the midpoint of the measured point deviation value after angle compensation as the tool length compensation value for the machining program is as follows: Among them, the tool length compensation value is L t ,δ′ max ,δ′ min These are the maximum and minimum deviation values ​​after angle compensation, respectively.

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