Research On Robot Trajectory Planning For Spray Painting Of Complex Free-form Surface

Spray painting is widely used in automotive,furniture and other fields.Using robots instead of human to spray can improve the efficiency significantly.Achieving an adaptable and efficient method of spray trajectory planing is the focal point and difficult point of the painting robot.Because the spray trajectory can be reused after being planned,the painting robot is widely used in large-scale production environment where the amount of the same kind objects is large,and the trajectory is planed by teaching.But teaching is inefficiency which make it not useful in small-scale production environment where there are various objects and the amount of each kind is small.Moreover,the quality of the trajectory depends on the artificial experience completely which means the high requirements of people.Besides,the hazardous substances cannot be ignored.In view of the above problems,this paper proposed an off-line spray trajectory planing system for complex free-form surfaces which combines auto trajectory planing and off-line teaching.In order to achieve off-line trajectory planing,model preprocessing and surface segmentation are studied firstly.By removing the noise,extracting the information and surface segmentation,the model suitable for trajectory planning is obtained.In the part of auto trajectory planing,trajectory points are obtain by the slicing process which find the intersection between the model and a set of plane.Then the trajectory points are sorted and cut,and the directions of painting are set to get the origin trajectory.After that,the method that combine polynomial fitting and spline interpolation is proposed to get the smooth trajectory points with specific intervals.Then taking the cartesian robot as an example,the attitude algorithm is introduced and the method to solve the problems caused by singular points is proposed.After introducing the core algorithms,the off-line spray trajectory planing system is built.The system integrates the core algorithms and introduces the human-computer interface and the information display interface.Visualized and convenient off-line teaching is achieved based on the interfaces,and some auxiliary functions are introduced to promote efficiency.Finally,the robot motion simulation and spray simulation is introduced to test the spray trajectory.After introducing the existing spray simulation method,a more concise method of modeling is proposed.The performance of the trajectory is shown visually by simulation.The actual experiments is done to test the performance of the trajectory more accurately and verify the feasibility of the method proposed.