Automatic wire laying linear axis solving method

Abstract

The invention discloses an automatic wire laying linear axis solving method, which belongs to the technical field of automatic laying and forming of prepreg tows, and comprises the following steps: step 1, reading initial path information of wire laying; step 2, reading robot information; thirdly, the fixed extension distance of the robot is set to be # imgabs0 #; 4, calculating an origin coordinate system of the joint coordinate system {5} according to the poses of the track points, wherein the origin coordinate value of the joint coordinate system {5} is as shown in the specification; 5, according to the set fixed extension distance, the origin coordinate of the first axis joint coordinate system {1} of the robot is calculated; and 6, taking the value as the final solving value of the linear axis of the track point, judging whether the final solving value is the last track point, if not, taking i = i + 1, and skipping to the step 5, and if yes, ending solving.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic placement and forming of prepreg tows, and particularly to a method for solving the linear axis of automatic fiber placement. Background Art

[0002] The automatic fiber placement technology is a forming manufacturing method proposed according to the manufacturing requirements of solid rocket motors in the United States and has now been widely commercialized. The fiber placement technology uses multiple fiber tows with smaller widths and can complete the manufacturing of composite material structural parts with more complex curved surfaces. This technology provides technical support for the low-cost and rapid manufacturing of high-performance composite lightweight structures, enables the manufacture of complex lightweight structural forms, expands the structural forms of lightweight structures, and further expands the application scope of composite lightweight structures.

[0003] The automatic fiber placement technology is a technology in which a multi-axis linkage placement head bundles multiple prepreg tows into a prepreg narrow band with a variable width through functions such as feeding, heating, laying, compressing, cutting, and restarting according to the path planned by the process, and then places it on the surface of the mold heated by the heating mechanism. To ensure that the placement head moves relative to the mold according to the planned position and posture, the fiber placement head needs to have more than six degrees of freedom. At the same time, as composite parts gradually develop towards large-size integration, automatic fiber placement equipment is generally equipped with linear guides, which introduce redundant degrees of freedom into the fiber placement system, making the inverse kinematics solution of the fiber placement equipment uncertain and increasing the operation risk of the equipment. How to quickly and effectively calculate the linear axis based on the placement path data is an important prerequisite for determining the inverse kinematics solution of the fiber placement system and is also the core technology for improving the movement flexibility of the equipment and reducing the operation risk of the equipment. As the structural shapes of composite parts become increasingly complex, traditional solution methods can no longer meet the requirements, and problems such as robot unreachability and overrun often occur. Therefore, it is urgent to propose an effective linear axis solution strategy to improve the reachability and flexibility of the movement of the fiber placement equipment, ensure the continuity and smoothness of the movement of the positioner during the fiber placement process to the greatest extent, improve the stability of the fiber placement process, and enhance the fiber placement efficiency and quality. Summary of the Invention

[0004] The present invention aims to solve the problem that the commonly used method for solving the linear axis in the prior art is the fixed position or linear interpolation method. When laying parts with complex shapes, especially when the curvature of the part changes greatly, the linear axis cannot make adaptive adjustments with the change of the curved surface, and problems such as robot unreachability and overrun often occur. The present invention provides a method for solving the linear axis of automatic fiber placement. For complex parts with large curvature changes, a new control method for the linear axis is added to ensure that the robot completes the task in a more appropriate posture, greatly increasing the reachability of the laying operation, solving the overrun problem, and increasing the movement flexibility of the equipment.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] An automatic fiber placement linear axis solving method includes the following steps:

[0007] Step 1: Read the initial fiber placement path information;

[0008] Step 2: Read the robot information;

[0009] Step 3: Set the fixed extension distance of the robot to L E ;

[0010] Step 4: Calculate the origin coordinate system of the joint coordinate system {5} according to the pose of the trajectory point P i P W P 5 i = W P i ×T T5 , then the origin coordinate value of the joint coordinate system {5} is ([[]] W x 5 i,W y 5 i,W z 5 i );

[0011] Step 5: Calculate the origin W x 1 i coordinate of the first axis joint coordinate system {1} of the robot according to the set fixed extension distance;

[0012] Step 6: Take the W x 1 i value as the final solution value of the linear axis of this trajectory point, and judge whether it is the last trajectory point. If not, take i = i + 1 and jump to Step 5. If so, the solution ends.

[0013] Preferably, in Step 1, the initial fiber placement path information is read and discretized into a series of trajectory points (P0, P1,..., P n-1 ), where n is the number of trajectory points.

[0014] Preferably, in Step 1, calculate the position information of the i-th fiber placement trajectory point P i in the world coordinate system {W} W P i ( W x i,W y i,W z i ), where W x i,W y i,W z i are the position coordinate quantities of the i-th trajectory point.

[0015] Preferably, in the second step, the relative position between the tool coordinate system and the fifth-axis joint coordinate system remains unchanged all the time. Read the robot tool coordinate system {T} and the fifth-axis joint coordinate system {5}, and calculate the transformation relationship from the joint coordinate system {5} to the tool coordinate system {T} as T T5 .

[0016] Preferably, in the second step, calculate the projection distance a1 between the origin of coordinate system {2} and the origin of coordinate system {1} in the XY plane.

[0017] Preferably, the calculation formula for the projection distance a1 is:

[0018] Preferably, in the fifth step, the following steps are included:

[0019] S51: According to the stretching distance, the origin of the joint coordinate system {2} W z 2 coordinate and the origin of the joint coordinate system {5} W z 5 i coordinate, calculate the projection length r of the stretching distance in the XY plane;

[0020] S52: In the XY plane, calculate the origin of the joint coordinate system {1} W x 1 i coordinate.

[0021] Preferably, in S51, when the robot model is fixed, the origin of the joint coordinate system {2} W z 2 coordinate belongs to a fixed value.

[0022] Preferably, the calculation formula for the projection length r is:

[0023] Preferably, W x 1 i The calculation formula for the coordinate is:

[0024] The beneficial effects of this technical solution are as follows:

[0025] 1. An automatic fiber placement linear axis solving method provided by the present invention, aiming at complex parts with large curvature changes, adds a control method for a linear axis. Through this method, it can ensure that the robot completes tasks in a more appropriate posture to the greatest extent, improve the accessibility and flexibility of the movement of the fiber placement equipment, and ensure the continuity and smoothness of the movement of the positioner during the fiber placement process to the greatest extent, improve the stability of the fiber placement process, and improve the fiber placement efficiency and fiber placement quality.

[0026] 2. An automatic fiber placement linear axis solving method provided by the present invention adds a control method for a linear axis for complex parts with large curvature changes. By this method, the downtime and on-site commissioning costs caused by no solution or calculation errors are avoided, and the overall production cost is effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flowchart in the present invention;

[0028] Figure 2 is an example of the present invention;

[0029] Figure 3 is a schematic diagram of the stretching amount calculation principle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be further described in detail below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

[0031] Embodiment 1

[0032] As Figures 1-3 shown, an automatic fiber placement linear axis solving method includes the following steps:

[0033] Step 1: Read the initial fiber placement path information;

[0034] Step 2: Read the robot information;

[0035] Step 3: Set the fixed stretching distance of the robot to I E ;

[0036] Step 4: Calculate the origin coordinate system of the joint coordinate system {5} according to the pose of the trajectory point P i P W P 5 i = W P i ×T T5 , then the origin coordinate value of the joint coordinate system {5} is ( W x 5 i,W y 5 i,W z 5 i );

[0037] Step 5: Calculate the origin W x 1 i coordinate of the first axis joint coordinate system {1} of the robot according to the set fixed stretching distance;

[0038] Step 6: With W x 1i The value is the final solved value of the linear axis of the trajectory point. Determine whether it is the last trajectory point. If not, set i = i + 1 and jump to Step Five. If so, the solution is completed.

[0039] Embodiment 2

[0040] An automatic fiber placement linear axis solving method includes the following steps:

[0041] Step One: Read the initial fiber placement path information;

[0042] Step Two: Read the robot information;

[0043] Step Three: Set the fixed extension distance of the robot to be L E ;

[0044] Step Four: Calculate the origin coordinate system of the joint coordinate system {5} according to the pose of the trajectory point P i P W P 5 i = W P i ×T T5 , then the origin coordinate value of the joint coordinate system {5} is ([[]] W x 5 i,W y 5 i,W z 5 i );

[0045] Step Five: Calculate the origin W x 1 i coordinate of the first axis joint coordinate system {1} of the robot according to the set fixed extension distance;

[0046] Step Six: Use W x 1 i the value as the final solved value of the linear axis of this trajectory point, and determine whether it is the last trajectory point (i.e., whether i is equal to n - 1). If not, set i = i + 1 and jump to Step Five. If so, the solution is completed.

[0047] Among them, in the above Step One, read the initial fiber placement path information and discretize it into a series of trajectory points (P0, P1,..., P n-1 ), where n is the number of trajectory points.

[0048] Among them, in the above Step One, calculate the position information of the i-th fiber placement trajectory point P i in the world coordinate system {W} Among them W x i,W y i,Wz i is the position coordinate quantity of the i-th trajectory point.

[0049] Among them, in the second step, the relative position between the tool coordinate system and the fifth-axis joint coordinate system remains unchanged all the time. Read the robot tool coordinate system {T} and the fifth-axis joint coordinate system {5}, and calculate the transformation relationship from the joint coordinate system {5} to the tool coordinate system {T} as T T5 .

[0050] Among them, in the second step, calculate the projection distance a between the origin of the coordinate system {2} and the origin of the coordinate system {1} in the XY plane 1 .

[0051] Among them, the calculation formula of the projection distance a1 is:

[0052] Among them, in the fifth step, the following steps are included:

[0053] S51: According to the extension distance, the origin of the joint coordinate system {2} W z 2 coordinates and the origin of the joint coordinate system {5} W z 5 i coordinates, calculate the projection length r of the extension distance in the XY plane;

[0054] S52: In the XY plane, calculate the origin of the joint coordinate system {1} W x 1 i coordinates.

[0055] Among them, in S51, when the robot model is fixed, the origin of the joint coordinate system {2} W z 2 coordinates belong to fixed values.

[0056] Among them, the calculation formula of the projection length r is:

[0057] Among them, W x 1 i the calculation formula of the coordinates is:

[0058] The beneficial effects of this technical solution are as follows:

[0059] 1. An automatic fiber placement linear axis solution method provided by the present invention. For complex parts with large curvature changes, a new control method for the linear axis is added. Through this method, it can ensure that the robot completes tasks in a more appropriate posture to the greatest extent, improve the accessibility and flexibility of the movement of the fiber placement equipment, and ensure the continuity and smoothness of the movement of the positioner during the fiber placement process to the greatest extent, improve the stability of the fiber placement process, and enhance the fiber placement efficiency and quality.

[0060] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for solving the linear axis of automatic wire placement, characterized in that: The following steps are involved: Step 1: Read the initial path information of the wire laying; Step 2: Read robot information; Step 3: Set the robot's fixed extension distance to L E ; Step 4: According to the trajectory point P i Pose calculation joint coordinate system {5} origin coordinate system W P 5 i = W P i ×T T5 , then the origin coordinate value of the joint coordinate system {5} is ( W x 5 i,W y 5 i,W z 5 i ); Step 5: Calculate the origin of the robot's first axis joint coordinate system {1} based on the set fixed extension distance W x 1 i coordinate; Step 6: W x 1 i The value is the final solution value of the linear axis of the trajectory point. Determine whether it is the last trajectory point. If not, take i=i+1 and jump to step 5. If so, the solution ends.

2. The method for solving the linear axis of automatic wire placement according to claim 1, characterized in that: In the step 1, the initial path information of the laying wire is read and discretized into a series of trajectory points (P0, P1, ..., P n-1 ), where n is the number of trajectory points.

3. The method for solving the linear axis of automatic wire placement according to claim 2, characterized in that: In the step 1, the i-th wire laying trajectory point P is calculated. i Position information in the world coordinate system {W} in W x i,W y i,W z i is the position coordinate of the i-th trajectory point.

4. The method for solving the linear axis of automatic wire placement according to claim 3, characterized in that: In the step 2, the relative position of the tool coordinate system and the fifth-axis joint coordinate system remains unchanged, the robot tool coordinate system {T} and the fifth-axis joint coordinate system {5} are read, and the transformation relationship from the joint coordinate system {5} to the tool coordinate system {T} is calculated as T T5 .

5. The method for solving the linear axis of automatic wire placement according to claim 4, characterized in that: In the step 2, the projection distance a1 between the origin of the coordinate system {2} and the origin of the coordinate system {1} in the XY plane is calculated.

6. The method for solving the linear axis of automatic wire placement according to claim 5, characterized in that: The calculation formula for projection distance a1 is:

7. The method for solving the linear axis of automatic wire placement according to claim 6, characterized in that: The step five includes the following steps: S51: Based on the stretching distance, the origin of the joint coordinate system {2} W z 2 Coordinates and joint coordinate system {5} origin W z 5 i Coordinates, calculate the projection length r of the stretching distance in the XY plane; S52: Calculate the origin of the joint coordinate system {1} in the XY plane W x 1 i coordinate.

8. The method for solving the linear axis of automatic wire placement according to claim 7, characterized in that: In S51, the robot model is fixed, and the origin of the joint coordinate system {2} W z 2 The coordinates are fixed values.

9. The method for solving the linear axis of automatic wire placement according to claim 8, characterized in that: The calculation formula of the projection length r is:

10. The method for solving the linear axis of automatic wire placement according to claim 9, characterized in that: W x 1i The coordinates are calculated as follows:

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