Track planning method for automatic spraying of aircraft

Abstract

A trajectory planning method for automatic spraying of an aircraft comprises the steps that firstly, the surface of the aircraft is divided into a plurality of spraying areas according to the coverage range of a spraying robot, then the spraying robot station of each spraying area is determined, and trajectory planning of each station of the spraying robot is completed in off-line programming software; and whether the track of the spraying robot interferes with or cannot cover all the spraying areas or not is judged, and finally a final spraying track program is generated according to track planning of all the spraying areas. The spraying quality is higher, accurate planning can be conducted according to the characteristics of the workpiece, coating is evenly covered, the problems of uneven coating, spraying leakage and re-spraying are avoided, and accurate spraying can also be conducted on parts with complex shapes and high-precision requirements.

Description

Technical Field

[0001] This invention relates to the field of trajectory planning technology, and in particular to a trajectory planning method for automatic spraying of aircraft. Background Technology

[0002] Robotic painting generally adopts a teaching mode, in which the operator plans the painting path in advance, controls the robot to reach the predetermined position through the teaching pendant, and saves the corresponding instruction program. Then, the robot will repeat the automatic painting according to the saved program. This method can meet the requirements for painting simple surfaces such as flat surfaces. However, when dealing with complex curved surfaces, it inevitably has disadvantages such as a complicated teaching process, long time consumption, high skill requirements for operators, and limitations on the placement of workpieces. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a trajectory planning method for automatic spraying of aircraft, so as to solve the problems in the background art mentioned above.

[0004] The technical problem solved by this invention is achieved by the following technical solution: A trajectory planning method for automatic painting of aircraft, the specific steps of which are as follows: 1) Based on the coverage of the painting robot, the surface of the aircraft is divided into several painting areas to ensure that the area of ​​all painting areas is within the coverage of the painting robot. 2) The initial positioning of the spraying robot in each spraying area was determined through motion simulation; 3) Based on the station information of the painting robot determined in step 2), complete the trajectory planning of each station of the painting robot in the offline programming software; 4) After the painting robot's station trajectory planning in step 3) is completed, the station is simulated using offline programming software to determine whether there is interference in the painting robot's trajectory or whether it cannot cover all painting areas. If so, the station information is modified and the process returns to step 3); if not, the station is recorded as a valid station. 5) Check if all painting areas have been traversed. If yes, plan the trajectory based on the updated station information; otherwise, change the painting area and return to step 2). 6) Based on the trajectory planning of all spraying areas, the final spraying trajectory program is generated. This program consists of two parts: the offline programming trajectory of the spraying robot and its corresponding station information. The offline programming trajectory and station information are automatically sent to the control system, which then controls the spraying robot to perform spraying.

[0005] In this invention, in step 3), the trajectory planning calculation for the spraying robot's position is as follows: Establish the coordinate system of the painting robot as the reference coordinate system of the positioning and detection system, set the coordinates of the marker point on the aircraft in the reference coordinate system, and measure the coordinates of the same marker point on the three-dimensional digital model. The coordinates of the two points satisfy rigid body dynamics, and then calculate the mathematical relationship between the two. Select n≥2 marker points on the aircraft, substitute the coordinates of each marker point into the mathematical formula, and use the least squares method to find the transformation relationship between the actual parking pose of the aircraft and its pose in the offline programming environment. Combine the transformation relationship between the aircraft pose and the world coordinate system in the offline programming environment to obtain the pose relationship between the aircraft pose and the world coordinate system in the actual operation state, which serves as the necessary data input for the trajectory automatic adjustment module. The automatic trajectory adjustment module in the offline programming software adjusts the position of the painting robot based on the actual pose of the aircraft obtained by the pose detection and analysis system. This means adjusting the movement trajectory of the painting robot's moving mechanism to ensure that the relative pose transformation between the actual painting position of the painting robot and the aircraft coordinate system is the same as that in the theoretical digital model. Since the position of the aircraft changes, the automatic trajectory adjustment module adjusts the position of the painting robot and moves the painting robot. Finally, the world coordinate system is introduced, and through coordinate transformation and corresponding algorithm calculations, the target positions that each axis of the moving mechanism needs to reach to ensure that the pose relationship between the aircraft and the robot remains unchanged are obtained, and thus the movement amount of each axis of the moving mechanism is obtained. Beneficial effects

[0006] 1) The present invention has higher spraying quality, can be precisely planned according to the characteristics of the workpiece, so that the coating is evenly covered, avoiding problems such as uneven coating, missed spraying, and re-spraying. It can also accurately spray on complex shapes and high-precision areas. 2) This invention improves efficiency, optimizes the spraying path, reduces unnecessary actions, and shortens time; it can operate continuously, is not affected by human factors, and is suitable for mass production. 3) This invention has high material utilization, precise control of spraying amount and atomization effect, reduces paint waste, and reduces rework due to quality problems; 4) This invention is more flexible, can quickly generate spraying trajectories for workpieces of different shapes, and can also be quickly adjusted and optimized according to changes in production needs; 5) This invention has good safety, reduces personnel exposure to harmful substances, and lowers safety risks caused by operational errors and robot malfunction. Attached Figure Description

[0007] Figure 1 This is a flowchart of trajectory planning in a preferred embodiment of the present invention.

[0008] Figure 2 This is a schematic diagram illustrating the pose relationship between the actual and theoretical digital models of the aircraft in a preferred embodiment of the present invention.

[0009] Figure 3 This is a schematic diagram of the automatic trajectory adjustment module in a preferred embodiment of the present invention.

[0010] Figure 4 This is a schematic diagram illustrating the relationship between the aircraft coordinate system, the base coordinate system of the painting robot, and the world coordinate system in a preferred embodiment of the present invention. Detailed Implementation

[0011] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0012] A trajectory planning method for automatic painting of aircraft, the specific steps of which are as follows: 1) Based on the coverage of the painting robot, the surface of the aircraft is divided into several painting areas to ensure that the area of ​​all painting areas is within the coverage of the painting robot. 2) The initial positioning of the spraying robot in each spraying area was determined through motion simulation; 3) Based on the station information of the painting robot determined in step 2), complete the trajectory planning of each station of the painting robot in the offline programming software; 4) After the painting robot's station trajectory planning in step 3) is completed, the station is simulated using offline programming software to determine whether there is interference in the painting robot's trajectory or whether it cannot cover all painting areas. If so, the station information is modified and the process returns to step 3); if not, the station is recorded as a valid station. 5) Check if all painting areas have been traversed. If yes, plan the trajectory based on the updated station information; otherwise, change the painting area and return to step 2). 6) Based on the trajectory planning of all spraying areas, the final spraying trajectory program is generated. This program consists of two parts: the offline programming trajectory of the spraying robot and its corresponding station information. The offline programming trajectory and station information are automatically sent to the control system, which then controls the spraying robot to perform spraying.

[0013] In this embodiment, in step 3), the trajectory planning calculation for the spraying robot's position is as follows: like Figure 2 As shown, the coordinate system of the painting robot is established as the reference coordinate system B of the positioning and detection system, and the coordinates P of the marker point on the aircraft measured in the reference coordinate system are set. T The coordinates P of the same landmark point are measured on the three-dimensional digital model. S If the coordinates of two points satisfy rigid body dynamics, then the mathematical relationship between them can be calculated. To improve the accuracy of pose determination, n≥2 marker points are selected on the aircraft. The coordinates of each marker point are substituted into the mathematical formula, and the least squares method is used to find the transformation relationship between the actual parking pose of the aircraft and its pose in the offline programming environment. Combined with the transformation relationship between the aircraft pose and the world coordinate system in the offline programming environment, the pose relationship between the aircraft pose and the world coordinate system under the actual operation state is obtained, which serves as the necessary data input for the trajectory automatic adjustment module. The automatic trajectory adjustment module in the offline programming software adjusts the position of the painting robot based on the actual aircraft pose obtained from the pose detection and analysis system. This adjustment involves modifying the movement trajectory of the painting robot's moving mechanisms (including the X, Z, C, and Y axes) to ensure that the relative pose transformation between the actual painting robot position and the aircraft coordinate system is the same as that in the theoretical digital model. Figure 3 As shown, {P S} and {B S} represent the states of the fixed coordinate systems of the aircraft and the painting robot in the offline programming state, respectively, while P R and B R This represents the coordinate system state of the aircraft and the painting robot in their actual state. Due to the change in the position of the aircraft ({P) S}→{P R Therefore, the trajectory automatic adjustment module adjusts the position of the painting robot, moving the painting robot from {B}. S Move to {B} R However, the transformation of the painting robot relative to the aircraft coordinate system under theoretical state M and actual state N remains unchanged, i.e., T S =T R ; The coordinate transformation relationship between the painting robot and the aircraft is as follows: Figure 4 As shown, the world coordinate system {W} is introduced. Through coordinate transformation and corresponding algorithm calculation, the target position that each axis of the mobile mechanism needs to reach in order to ensure that the pose relationship between the aircraft and the robot remains unchanged is obtained, and then the movement amount of each axis of the mobile mechanism is obtained. The outer surface of the aircraft is a large curved surface, the volume of which is much larger than the range of motion of a single painting robot. In order for the painting robot to cover all the surfaces of the aircraft, the painting robot's moving mechanism needs to expand its range of motion. When the painting robot is in a certain position, the area it can paint is fixed. Therefore, the entire surface of the aircraft is divided into several curved blocks, and each curved block corresponds to a position. The painting robot can completely paint this curved block at this position. Therefore, by using the moving mechanism to transport the painting robot to several positions, the painting robot can completely cover the entire outer surface of the aircraft.

[0014] The specific embodiments described herein are merely illustrative examples of the present invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or adopt similar methods to replace them, but without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A trajectory planning method for automatic spraying of paint on aircraft, characterized in that, First, based on the coverage area of ​​the painting robot, the surface of the aircraft is divided into several painting areas. Then, the position of the painting robot in each painting area is determined. Next, the trajectory planning of each position of the painting robot is completed in the offline programming software, and it is determined whether there is any interference in the trajectory of the painting robot or whether it cannot cover all painting areas. Finally, based on the trajectory planning of all painting areas, the final painting trajectory program is generated.

2. The trajectory planning method for automatic spraying of an aircraft according to claim 1, characterized in that, The specific steps are as follows: 1) Based on the coverage area of ​​the painting robot, the surface of the aircraft is divided into several painting areas; 2) The initial positioning of the spraying robot in each spraying area was determined through motion simulation; 3) Based on the station information of the painting robot determined in step 2), complete the trajectory planning of each station of the painting robot in the offline programming software; 4) After the painting robot's station trajectory planning in step 3) is completed, the station is simulated using offline programming software to determine whether there is interference in the painting robot's trajectory or whether it cannot cover all painting areas. If so, the station information is modified and the process returns to step 3); if not, the station is recorded as a valid station. 5) Check if all painting areas have been traversed. If yes, plan the trajectory based on the updated station information; otherwise, change the painting area and return to step 2). 6) Generate the final spraying trajectory program based on the trajectory planning of all spraying areas.

3. The trajectory planning method for automatic spraying of an aircraft according to claim 2, characterized in that, In step 3), the trajectory planning calculation for the painting robot's station position is as follows: Establish the coordinate system of the painting robot as the reference coordinate system of the positioning and detection system, set the coordinates of the marker point on the aircraft in the reference coordinate system, and measure the coordinates of the same marker point on the three-dimensional digital model. The coordinates of the two points satisfy rigid body dynamics, and then calculate the mathematical relationship between the two. Substituting the coordinates of each marker point into the mathematical formula, the least squares method is used to determine the transformation relationship between the actual parking pose of the aircraft and its pose in the offline programming environment. Combining the transformation relationship between the aircraft pose and the world coordinate system in the offline programming environment, the pose relationship between the aircraft pose and the world coordinate system under actual operation is obtained, serving as the necessary data input for the trajectory automatic adjustment module. The trajectory automatic adjustment module in the offline programming software adjusts the position of the painting robot, i.e., adjusts the motion trajectory of the painting robot's moving mechanism, based on the actual pose of the aircraft obtained from the pose detection and analysis system. This ensures that the relative pose transformation between the actual painting position of the painting robot and the aircraft coordinate system is the same as that under the theoretical numerical model. Since the position of the aircraft changes, the trajectory automatic adjustment module adjusts the position of the painting robot and moves the painting robot. Finally, the world coordinate system is introduced, and through coordinate transformation and corresponding algorithm calculations, the target positions that each axis of the moving mechanism needs to reach to ensure that the pose relationship between the aircraft and the robot remains unchanged are obtained, thus obtaining the movement amount of each axis of the moving mechanism.

4. The trajectory planning method for automatic spraying of an aircraft according to claim 3, characterized in that, Select n≥2 markers on the aircraft.

5. The trajectory planning method for automatic spraying of an aircraft according to claim 1, characterized in that, In step 6), the spraying trajectory program is divided into two parts: the offline programming trajectory of the spraying robot and its corresponding station information.

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