Method for detecting plane gradient and optimizing machining precision

Abstract

The invention relates to a method for detecting the gradient of a plane and optimizing the machining precision, and the method comprises the following steps: (1), carrying out the preliminary path collection processing of the plane at the current position before the actual machining; (2) carrying out optimal feature point selection based on the acquired data set; (3) carrying out plane fitting processing based on the selected optimal feature point; (4) calculating a normal vector of the current position plane and a corresponding base vector based on the selected optimal feature point; (5) constructing a local coordinate system based on the current position, and calculating transformation between the local coordinate system and the workpiece global coordinate system; and (6) optimizing the machining path of the cutting head according to the local coordinate system. By adopting the method for detecting the inclination of the plane and optimizing the machining precision, the machining path is optimized according to the local coordinate system, so that the machining precision is effectively improved, and errors caused by inclination of the workpiece are reduced.

Description

Technical Field

[0001] The present invention relates to the field of laser cutting, in particular to plate surface inclination detection, and specifically refers to a method for detecting plane inclination and optimizing processing accuracy. Background Art

[0002] In the field of mechanical processing, the plane inclination of the workpiece will significantly affect the processing accuracy. In the traditional processing process, it is assumed that the plane of the workpiece is parallel to the reference coordinate system of the processing equipment, but in fact, due to installation errors, material deformation or deviation of the processing benchmark, the plane of the workpiece may have an unknown inclination. This inclination leads to the following problems:

[0003] Reduced machining accuracy: The deviation between the workpiece plane and the reference coordinate system causes errors in the machining path, resulting in the actual machining results not being consistent with the design.

[0004] Complex equipment adjustment: In order to eliminate the influence of tilt, the traditional method requires manual adjustment of the workpiece position, which is time-consuming and difficult to ensure accurate adjustment.

[0005] Limited automation: Existing processing equipment cannot identify the inclination of the workpiece in real time and lacks the ability to make adaptive adjustments based on the actual state of the workpiece.

[0006] In view of the above technical problems, the existing technology generally adopts the following processing flow:

[0007] Manual leveling: After the workpiece is installed, its plane inclination is detected by measuring tools (such as a level, micrometer), and then the workpiece posture is manually adjusted to make it as parallel to the equipment coordinate system as possible.

[0008] Indirect correction: For some complex workpieces, the tilt effect can be reduced by adding a precision adjustment mechanism to the fixture or base, but this usually increases costs and is less efficient.

[0009] Ignoring inclination: In some cases, machining is performed directly according to the designed path, ignoring the influence of inclination, resulting in large machining errors, especially for high-precision workpieces.

[0010] In this regard, the above practical problems usually face the following practical defects:

[0011] The measurement and adjustment process is cumbersome: it requires repeated measurement and adjustment many times, which reduces production efficiency.

[0012] Unstable adjustment accuracy: Manual adjustment has errors and is difficult to meet high-precision processing requirements.

[0013] Low level of automation: It is difficult to integrate with automated equipment and cannot adapt to the development needs of intelligent manufacturing. Summary of the invention

[0014] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a method for detecting the inclination of a plane and optimizing the machining accuracy.

[0015] In order to achieve the above object, the method for detecting plane inclination and optimizing machining accuracy of the present invention is as follows:

[0016] The method for detecting the inclination of a plane and optimizing machining accuracy is mainly characterized in that the method comprises the following steps:

[0017] (1) Before actual processing, preliminary path acquisition and processing is performed on the current position plane;

[0018] (2) Select the optimal feature points based on the collected data set;

[0019] (3) Performing plane fitting based on the selected optimal feature points;

[0020] (4) Calculate the normal vector of the current position plane and the corresponding basis vector based on the selected optimal feature point;

[0021] (5) Construct a local coordinate system based on the current position and calculate the transformation between the local coordinate system and the workpiece global coordinate system;

[0022] (6) Optimizing the cutting head processing path according to the local coordinate system.

[0023] Preferably, the step (1) is specifically as follows:

[0024] Before actual processing, the cutting head is controlled to move along the original graphic path, and the spatial coordinate data of all discrete points on the graphic surface are collected to form an initial point cloud data set, thereby completing the preliminary path collection.

[0025] Preferably, the step (2) is specifically as follows:

[0026] Select three points from the point cloud data set to form a combination of points with the largest triangle area, and determine the optimal feature point group by comparing the possible combinations of the four points above, below, left and right or the possible combinations of all points. That is, the small area where the original figure or the original cutting path is located is close to a plane. In order to accurately determine the plane where the entire area is located, three points that are relatively scattered in the point cloud data, that is, far apart from each other, are selected. In order to achieve this goal, the three points that form the largest triangle area can be selected from the four points on the left, top, right, and bottom as plane feature points.

[0027] Preferably, the step (3) is specifically as follows:

[0028] Using the three selected optimal feature points, the plane equation of the current position of the surface of the figure is calculated through geometric deduction, and the plane fitting process is performed. Three optimal feature points are obtained. Since three points determine a plane, the plane equation of the small area where the figure is located can be determined through geometric calculation.

[0029] Preferably, the step (4) comprises:

[0030] The normal vector of the current plane is determined based on the three selected optimal feature points. The direction vector of the plate boundary obtained by the plate edge finding function is combined to derive the basis vector, which is:

[0031] The three selected optimal feature points are recorded as A, B, and C in counterclockwise order, and the normal vector of the plane is v z =AB×AC, and combined with the existing plate edge finding function, we can get two basis vectors v in the horizontal direction. x , v y , that is, we get all three basis vectors v x , v y ,v z .

[0032] Preferably, the step (5) comprises:

[0033] Based on the derived basis vector, a local coordinate system is constructed, and the transformation between the local coordinate system and the workpiece global coordinate system is calculated, specifically:

[0034] According to the three basis vectors v x , v y ,v z direction, construct the local coordinate system of the small area where the graphics are located. If the basis vector of the workpiece global coordinate system is w x , w y , w z , then the local coordinate system basis is B v =(v x , v y ,v z ), the workpiece global coordinate system base is B w =(w x , w y , w z ), then the transformation matrix M from the global coordinate system basis to the local coordinate system basis is: v =B w M.

[0035] Preferably, the step (6) comprises:

[0036] The path points in the global coordinate system of the workpiece are converted into coordinates in the local coordinate system in real time, and then the processing path is optimized according to the local coordinate system, specifically:

[0037] For any point p on the cutting graph, if its coordinates in the workpiece global coordinate system are C w , that is, p = B w C w , then its coordinate C in the local coordinate system can be obtained by transformation v , that is, p = B v C v ; According to the above transformation from the global coordinate system basis to the local coordinate system basis, we get C v =M -1 C w , the subsequent actual processing path uses coordinate C v Replace the original coordinate C w The influence of the inclination can be removed, thereby optimizing the processing path.

[0038] The method for detecting plane inclination and optimizing machining accuracy of the present invention has the following technical advantages:

[0039] Automatic detection of inclination: Through path acquisition technology and point cloud analysis, the plane inclination of the workpiece surface is automatically calculated without the need for additional measurement tools;

[0040] Efficient coordinate transformation: The local coordinate system is derived through the plane normal vector, and the transformation from the workpiece coordinate system to the processing equipment coordinate system is automatically completed without manual adjustment of the workpiece posture;

[0041] Improved processing accuracy: The path error caused by the inclination is compensated in real time into the processing path, which significantly improves the processing accuracy;

[0042] Simplify the operation process: replace the traditional manual leveling and fixture adjustment methods, realize full process automation, and greatly reduce the operation difficulty and time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the functional interface of the present invention during actual operation.

[0044] Figure 2 The figure is a flow chart of the method for detecting plane inclination and optimizing machining accuracy of the present invention. DETAILED DESCRIPTION

[0045] In order to more clearly describe the technical content of the present invention, further description is given below in conjunction with specific embodiments.

[0046] Before describing in detail embodiments according to the present invention, it should be noted that, hereinafter, the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, whereby a process, method, article or apparatus comprising a series of elements includes not only these elements, but also other elements not explicitly listed or inherent to such process, method, article or apparatus.

[0047] See also Figure 2 As shown, the method for detecting the inclination of a plane and optimizing the machining accuracy, wherein the method comprises the following steps:

[0048] (1) Before actual processing, preliminary path acquisition and processing is performed on the current position plane;

[0049] (2) Select the optimal feature points based on the collected data set;

[0050] (3) Performing plane fitting based on the selected optimal feature points;

[0051] (4) Calculate the normal vector of the current position plane and the corresponding basis vector based on the selected optimal feature point;

[0052] (5) Construct a local coordinate system based on the current position and calculate the transformation between the local coordinate system and the workpiece global coordinate system;

[0053] (6) Optimizing the cutting head processing path according to the local coordinate system.

[0054] As a preferred embodiment of the present invention, the step (1) is specifically:

[0055] Before actual processing, the cutting head is controlled to move along the original graphic path, and the spatial coordinate data of all discrete points on the graphic surface are collected to form an initial point cloud data set, thereby completing the preliminary path collection.

[0056] As a preferred embodiment of the present invention, the step (2) is specifically as follows:

[0057] Select three points from the point cloud data set to form a combination of points with the largest triangle area, and determine the optimal feature point group by comparing the possible combinations of the four points above, below, left and right or the possible combinations of all points. That is, the small area where the original figure or the original cutting path is located is close to a plane. In order to accurately determine the plane where the entire area is located, three points that are relatively scattered in the point cloud data, that is, far apart from each other, are selected. In order to achieve this goal, the three points that form the largest triangle area can be selected from the four points on the left, top, right, and bottom as plane feature points.

[0058] As a preferred embodiment of the present invention, the step (3) is specifically as follows:

[0059] Using the three selected optimal feature points, the plane equation of the current position of the surface of the figure is calculated through geometric deduction, and the plane fitting process is performed. That is, three optimal feature points are obtained. Since three points determine a plane, the plane equation of the small area where the figure is located can be determined through geometric calculation.

[0060] As a preferred embodiment of the present invention, the step (4) comprises:

[0061] The normal vector of the current plane is determined based on the three selected optimal feature points. The direction vector of the plate boundary obtained by the plate edge finding function is combined to derive the basis vector, which is:

[0062] The three selected optimal feature points are recorded as A, B, and C in counterclockwise order, and the normal vector of the plane is v z =AB×AC, and combined with the existing plate edge finding function, we can get two basis vectors v in the horizontal direction. x , v y , that is, we get all three basis vectors v x , v y , v z .

[0063] As a preferred embodiment of the present invention, the step (5) comprises:

[0064] Based on the derived basis vector, a local coordinate system is constructed, and the transformation between the local coordinate system and the workpiece global coordinate system is calculated, specifically:

[0065] According to the three basis vectors v x , v y , v z direction, construct the local coordinate system of the small area where the graphics are located. If the basis vector of the workpiece global coordinate system is w x , w y , w z , then the local coordinate system basis is B v =(v x , v y , v z ), the workpiece global coordinate system base is B w =(w x , w y , w z ), then the transformation matrix M from the global coordinate system basis to the local coordinate system basis is: v =B w M.

[0066] As a preferred embodiment of the present invention, the step (6) comprises:

[0067] The path points in the global coordinate system of the workpiece are converted into coordinates in the local coordinate system in real time, and then the processing path is optimized according to the local coordinate system, specifically:

[0068] For any point p on the cutting graph, if its coordinates in the workpiece global coordinate system are C w , that is, p = B w C w , then its coordinate C in the local coordinate system can be obtained by transformation v , that is, p = B v C v ; According to the above transformation from the global coordinate system basis to the local coordinate system basis, we get C v =M -1 C w , the subsequent actual processing path uses coordinate C v Replace the original coordinate C w The influence of the inclination can be removed, thereby optimizing the processing path.

[0069] In practical applications, this method can accurately identify the actual state of the workpiece by calculating the plane normal vector generated by the feature points. At the same time, the technology of automatically generating a local coordinate system according to the inclination of the workpiece and transforming it with the global coordinate system is used to eliminate processing errors. This processing path optimization method that combines coordinate transformation and path correction can adjust the processing path in real time to adapt to the actual inclination state of the workpiece.

[0070] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0071] It should be understood that each part of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device.

[0072] A person of ordinary skill in the art may understand that all or part of the steps of the method for implementing the above-mentioned embodiment may be completed by instructing the relevant hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0073] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0074] In the description of this specification, the description with reference to the terms "an embodiment", "some embodiments", "example", "specific example", or "embodiment" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0075] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

[0076] The method for detecting plane inclination and optimizing machining accuracy of the present invention has the following technical advantages:

[0077] Automatic detection of inclination: Through path acquisition technology and point cloud analysis, the plane inclination of the workpiece surface is automatically calculated without the need for additional measurement tools;

[0078] Efficient coordinate transformation: The local coordinate system is derived through the plane normal vector, and the transformation from the workpiece coordinate system to the processing equipment coordinate system is automatically completed without manual adjustment of the workpiece posture;

[0079] Improved processing accuracy: The path error caused by the inclination is compensated in real time into the processing path, which significantly improves the processing accuracy;

[0080] Simplify the operation process: replace the traditional manual leveling and fixture adjustment methods, realize full process automation, and greatly reduce the operation difficulty and time cost.

[0081] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it is apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.

Claims

1. A method for detecting plane inclination and optimizing machining accuracy, characterized in that: The method comprises the following steps: (1) Before actual processing, preliminary path acquisition and processing is performed on the current position plane; (2) Select the optimal feature points based on the collected data set; (3) Performing plane fitting based on the selected optimal feature points; (4) Calculate the normal vector of the current position plane and the corresponding basis vector based on the selected optimal feature point; (5) Construct a local coordinate system based on the current position and calculate the transformation between the local coordinate system and the workpiece global coordinate system; (6) Optimizing the cutting head processing path according to the local coordinate system.

2. The method for detecting plane inclination and optimizing machining accuracy according to claim 1, characterized in that: The step (1) is specifically as follows: Before actual processing, the cutting head is controlled to move along the original graphic path, and the spatial coordinate data of all discrete points on the graphic surface are collected to form an initial point cloud data set, thereby completing the preliminary path collection.

3. The method for detecting plane inclination and optimizing machining accuracy according to claim 2, characterized in that: The step (2) is specifically as follows: Select three points from the point cloud data set to form a triangle with the largest area, and determine the optimal feature point group by comparing the possible combinations of the four points above, below, left and right or the possible combinations of all points.

4. The method for detecting plane inclination and optimizing machining accuracy according to claim 3, characterized in that: The step (3) is specifically as follows: Using the three selected optimal feature points, the plane equation of the graphic surface at the current position is calculated through geometric deduction, and the plane fitting process is performed.

5. The method for detecting plane inclination and optimizing machining accuracy according to claim 4, characterized in that: The step (4) comprises: The normal vector of the current plane is determined based on the three selected optimal feature points. The direction vector of the plate boundary obtained by the plate edge finding function is combined to derive the basis vector, which is: The three selected optimal feature points are recorded as A, B, and C in counterclockwise order, and the normal vector of the plane is v z =AB×AC, and combined with the existing plate edge finding function, we can get two basis vectors v in the horizontal direction. x ,v y , that is, we get all three basis vectors v x ,v y ,v z .

6. The method for detecting plane inclination and optimizing machining accuracy according to claim 5, characterized in that: The step (5) comprises: Based on the derived basis vector, a local coordinate system is constructed, and the transformation between the local coordinate system and the workpiece global coordinate system is calculated, specifically: According to the three basis vectors v x ,v y ,v z direction, construct the local coordinate system of the small area where the graphics are located, if the basis vector of the workpiece global coordinate system is w x ,w y ,w z , then the local coordinate system basis is B v =(v x ,v y ,v z ), the workpiece global coordinate system base is B w =(w x ,w y ,w z ), then the transformation matrix M from the global coordinate system basis to the local coordinate system basis is: v =B w M.

7. The method for detecting plane inclination and optimizing machining accuracy according to claim 6, characterized in that: The step (6) comprises: The path points in the global coordinate system of the workpiece are converted into coordinates in the local coordinate system in real time, and then the processing path is optimized according to the local coordinate system, specifically: For any point p on the cutting graph, if its coordinates in the workpiece global coordinate system are C w , that is, p=B w C w , then its coordinate C in the local coordinate system can be obtained by transformation v , that is, p = B v C v ; According to the above transformation from the global coordinate system basis to the local coordinate system basis, we get C v =M -1 C w , the subsequent actual processing path uses coordinate C v Replace the original coordinate C w The influence of the inclination can be removed, thereby optimizing the processing path.

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