Off-line programming kinematics post-processing method of five-axis numerical control drilling machine tool

Abstract

The invention discloses an off-line programming kinematics post-processing method for a five-axis numerical control drilling machine tool, and belongs to the field of automatic drilling in airplane digital assembly. According to the position relation of a world coordinate system, an equipment coordinate system and a label coordinate system in a three-dimensional digital model of a product to be machined, the position relation of the world coordinate system, the equipment coordinate system and the label coordinate system is calculated through matrix operation; xYZ coordinates and A-axis and B-axis swing angles for equipment machining are obtained, and the off-line programming post-processing function of five-axis numerical control hole equipment can be achieved. By adopting the method provided by the invention, the accuracy of the data generated by the offline programming post-processing can be ensured, and meanwhile, the operation efficiency of the offline programming post-processing is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of automatic hole making in digital assembly of aircraft, and in particular to an off-line programming kinematics post-processing method for a five-axis numerical control hole making machine tool. Background Art

[0002] Five-axis CNC hole drilling machines are widely used in the automated hole making of aviation products (such as wing panels, fuselage panels, beams, ribs and other parts). Before product processing, offline programming software is usually used to plan the motion trajectory of the equipment and generate relevant instructions for automatic hole making.

[0003] Offline programming of five-axis CNC machine tools can be completed in two steps. First, the motion trajectory of the tool is planned in the workpiece coordinate system to generate a tool path planning file (tool path file). The tool information generated by tool path planning does not take into account the specific machine tool structure and CNC system type, and cannot be directly applied to CNC machine tool processing, and requires post-processing.

[0004] Post-processing technology is one of the key technologies of CNC machine tool offline programming technology. The post-processing of CNC programming is to transform the tool position data into a CNC machining program that can be recognized by the machine tool through the transformation of the machine tool kinematics, describe the movement of each axis of the machine tool, and control the machine tool processing movement.

[0005] Many scholars have conducted relevant research on offline programming post-processing technology, such as the document "Research on kinematic transformation of five-axis CNC machine tools and its post-processing methods, Wei Guangxi. Tianjin University of Technology, 2020, 11-17" and the document "Research and application of post-processing technology of five-axis CNC machine tools, Yang Zhi. Northeastern University, 2009, 22-25".

[0006] The above method defaults to describing the machining posture label in the device coordinate system, and calculates the angles of the two rotation axes of the five-axis CNC machine tool, but lacks the conversion process of the label from the world coordinate system to the device coordinate system. Summary of the invention

[0007] The purpose of the present invention is to provide an offline programming kinematic post-processing method for a five-axis CNC hole machine tool, which can convert labels from a world coordinate system to a device coordinate system, and can quickly calculate the X, Y, Z coordinates and the A-axis (axis rotating around the X-axis) and B-axis (axis rotating around the Y-axis) swing angles used for device processing.

[0008] In order to achieve the above-mentioned object, the off-line programming kinematic post-processing method of the five-axis CNC hole machine tool provided by the present invention comprises the following steps:

[0009] (1) Create a label (axis system) based on the outer surface of the wall panel and the axis of the hole in the 3D model of the product to be processed, and calculate the position matrix of the label in the world coordinate system

[0010] (2) Calculate the pose matrix of the device coordinate system in the world coordinate system

[0011] (3) Calculate the pose matrix of the tag in the device coordinate system

[0012] (4) Based on Get the hole-making point coordinates X, Y, Z and normal vector V in the equipment coordinate system N ;

[0013] (5) According to the normal vector V N , get the rotation angle D of the device A axis and B axis A and D B .

[0014] In the above technical solution, the two rotating axes of the machine tool refer to the A axis and the B axis respectively. The present invention obtains the XYZ coordinates and the swing angles of the A axis and the B axis for equipment processing through matrix operations based on the positional relationship between the world coordinate system, the equipment coordinate system and the label coordinate system in the three-dimensional digital model of the product to be processed. First, the pose matrix of the label in the world coordinate system and the pose matrix of the equipment coordinate system in the world coordinate system are calculated, and then the pose matrix of the label in the equipment coordinate system is calculated through the above two pose matrices, and then the XYZ coordinates and normal vectors used for equipment hole making are obtained, and finally the swing angles of the A axis and the B axis of the equipment are calculated according to the normal vector, which can realize the offline programming post-processing function of the five-axis digital control hole equipment.

[0015] Preferably, in step (1), the intersection of the hole axis and the outer surface of the wallboard is the origin of the tag, the Z axis of the tag coincides with the hole axis, and the pose matrix of the tag in the world coordinate system is a 4×4 square matrix, wherein the 3×3 matrix in the upper left corner is the linear representation of the tag X, Y and Z axes in the world coordinate system, and the first 3 elements of the last column are the coordinates of the tag origin in the world coordinate system, and then the matrix is ​​homogeneously transformed, in the following form:

[0016]

[0017] Preferably, in step (2), the pose matrix of the device coordinate system in the world coordinate system is It is the linear representation of the three coordinate axes and the origin of the device coordinate system in the world coordinate system;

[0018] Preferably, in step (3), the pose matrix of the tag in the device coordinate system is The calculation method is:

[0019] (3-1) The pose matrix of the device coordinate system in the world coordinate system Inverse, we get

[0020] (3-2) Calculate the pose matrix of the tag in the device coordinate system:

[0021]

[0022] Preferably, in step (4), the hole-making point coordinates X, Y, Z and the normal vector V in the equipment coordinate system are N The calculation method is:

[0023] (4-1) From the pose matrix of the tag in the device coordinate system Extract XYZ coordinates from:

[0024] X=o x ′ Y=o y ′ Z=o z '

[0025] (4-2) From the pose matrix of the tag in the device coordinate system Extract the normal vector V from N :

[0026]

[0027] Preferably, in step (5), the rotation angle D of the device A axis and B axis is A and D B The calculation method is:

[0028] (5-1) Calculate the rotation matrix around axis A and axis B

[0029]

[0030] (5-2) The Z axis of the device coordinate system is rotated by the matrix Converted to label normal vector V N

[0031]

[0032] (5-3) By calculating the corresponding elements of the left and right equations in (5-2) as equal, we get:

[0033] D B =sin -1 z i '

[0034]

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The off-line programming post-processing method of the five-axis CNC machine tool of the present invention proposes a kinematic transformation model of the five-axis CNC machine tool. According to the positional relationship between the world coordinate system, the equipment coordinate system and the label, the XYZ coordinates and the A-axis and B-axis swing angles of the equipment processing are calculated through translation and rotation transformation.

[0037] The off-line programming post-processing method of the five-axis CNC hole machine tool of the present invention has the characteristics of simple mathematical model and high calculation efficiency. On the basis of ensuring the accuracy of data generated by off-line programming post-processing, the calculation efficiency of off-line programming post-processing is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a world coordinate system, a device coordinate system, and a tag coordinate system according to an embodiment of the present invention;

[0039] Figure 2 The figure is a flowchart of the offline programming post-processing method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described below in conjunction with embodiments and accompanying drawings.

[0041] Example

[0042] Figure 1 This is a schematic diagram of a hole label coordinate system, world coordinate system and device coordinate system for an aircraft wall panel. The process of the off-line programming kinematic post-processing method of the five-axis CNC hole machine tool in this embodiment can be found in Figure 2 , which comprises the following steps:

[0043] S101, calculate the pose matrix of the tag in the world coordinate system:

[0044]

[0045] S102, calculating the pose matrix of the device coordinate system in the world coordinate system:

[0046]

[0047] S103, calculating the pose matrix of the device coordinate system in the world coordinate system:

[0048]

[0049] S104, obtain the hole-making point coordinates X, Y, Z and normal vector V in the equipment coordinate system N :First, from the pose matrix of the tag in the device coordinate system Extract XYZ coordinates from:

[0050] X=ox ′ Y=o y ′ Z=o z '

[0051] Then from the pose matrix of the tag in the device coordinate system Extract the normal vector V from N :

[0052] S105, calculating the rotation angle D of the device A axis and B axis A and D B :

[0053] D B =sin -1 z1′

[0054]

[0055] A scenario in which the technical solution of the present invention is actually used is as follows:

[0056] S101, calculate the pose matrix of the tag in the world coordinate system:

[0057]

[0058] S102, calculating the pose matrix of the device coordinate system in the world coordinate system:

[0059]

[0060] S103, calculate the pose matrix of the tag in the device coordinate system:

[0061]

[0062] S104, obtain the hole-making point coordinates X, Y, Z and normal vector V in the equipment coordinate system N :

[0063] First, the pose matrix of the tag in the device coordinate system Extract XYZ coordinates from:

[0064] X=o′ x =7176.141 Y=o′ y =4176.419 Z=o′ z =273.194

[0065] Then from the pose matrix of the tag in the device coordinate system Extract the normal vector V from N :

[0066]

[0067] S105, calculating the rotation angle D of the device A axis and B axis A and D B (Expressed in radians):

[0068] D B =sin -1 z i ′=sin -1 0.091=0.091

[0069]

[0070] The off-line programming post-processing method of the five-axis CNC machine tool of the present invention proposes a kinematic transformation model of the five-axis CNC machine tool, and calculates the XYZ coordinates of the equipment processing and the swing angles of the A axis and the B axis through translation and rotation transformation according to the positional relationship between the world coordinate system, the equipment coordinate system and the label. The off-line programming post-processing method of the five-axis CNC machine tool of the present invention has the characteristics of simple mathematical model and high calculation efficiency. On the basis of ensuring the accuracy of the data generated by the off-line programming post-processing, the calculation efficiency of the off-line programming post-processing is greatly improved.

Claims

1. A kinematic post-processing method for off-line programming of a five-axis CNC drilling machine tool, characterized in that: The following steps are involved: (1) Create labels based on the outer surface of the wall panel and the axis of the hole in the 3D model of the product to be processed, and calculate the position matrix of the label in the world coordinate system The label contains hole position and normal information of the product to be processed in the aircraft coordinate system; (2) Calculate the pose matrix of the device coordinate system in the world coordinate system The equipment coordinate system is the coordinate system of the five-axis CNC machine tool; (3) Calculate the pose matrix of the tag in the device coordinate system (4) Based on Get the hole-making point coordinates X, Y, Z and normal vector V in the equipment coordinate system N ; (5) According to the normal vector V N , get the rotation angle D of the device A axis and B axis A and D B .

2. The off-line programming kinematics post-processing method according to claim 1, characterized in that: In step (1), the intersection of the hole axis and the outer surface of the wall panel is the origin of the label. The Z axis of the label coincides with the hole axis. The position matrix of the label in the world coordinate system is a 4×4 square matrix, in which the 3×3 matrix in the upper left corner is the linear representation of the label X, Y and Z axes in the world coordinate system. The first three elements of the last column are the coordinates of the label origin in the world coordinate system. Then, the matrix is ​​homogeneously transformed, and the form is as follows:

3. The off-line programming kinematics post-processing method according to claim 2, characterized in that: Step (2) pose matrix It is the linear representation of the three coordinate axes and the coordinate origin of the device coordinate system in the world coordinate system.

4. The off-line programming kinematics post-processing method according to claim 3, characterized in that: The pose matrix of the label in the device coordinate system in step (3) The calculation method is: (3-1) The pose matrix of the device coordinate system in the world coordinate system Inverse, we get (3-2) Calculate the pose matrix of the tag in the device coordinate system:

5. The off-line programming kinematics post-processing method according to claim 4, characterized in that: The coordinates X, Y, Z and normal vector V of the hole point in the equipment coordinate system in step (4) N The calculation method is: (4-1) From the pose matrix of the tag in the device coordinate system Extract XYZ coordinates from: X=o x ′ Y=o y ′ Z=o z ′ (4-2) From the pose matrix of the tag in the device coordinate system Extract the normal vector V from N :

6. The off-line programming kinematics post-processing method according to claim 5, characterized in that: The rotation angle D of the device A and B axes in step (5) A and D B The calculation method is: (5-1) Calculate the rotation matrix around axis A and axis B (5-2) The Z axis of the device coordinate system is rotated by the matrix Converted to label normal vector V N (5-3) The rotation angle D of the device A axis and B axis is calculated by equalizing the corresponding elements in (5-2). A and D B .

7. The off-line programming kinematics post-processing method according to claim 6, characterized in that:

8. The off-line programming kinematics post-processing method according to claim 7, characterized in that: D B =sin -1 z i ′

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