Research On Robot Traction Operation In Weaving Process Of Composite Preforms

Because of its high specific modulus,high specific strength,and good designability,braided composite materials are widely used in various fields such as rail transit,aerospace,and wind power generation.At present,composite material preforms with special-shaped structures are braided with a core.Although the robot has been applied to the traction operation of the mandrel,the traction trajectory is mainly obtained through manual teaching.When the mandrel has bending or variable cross-section features,it will produce Big weaving error.When weaving large prefabricated parts,the clamping end of the single robot is far away from the center of gravity of the mandrel,which will lead to insufficient load or even the mandrel falling when the robot is pulling the mandrel and feeding,and only one end of the large mandrel is clamped Fixed,under the joint action of yarn force and gravity,it will cause the center line of the mandrel of the braided section to deviate from the center of the guide ring.Based on the above situation,this paper conducts corresponding research on the robot traction operation in the weaving process of composite material prefabricated parts,so as to improve the weaving quality and weaving efficiency of prefabricated parts.This paper analyzes the principle of the prefabricated weaving process,establishes a mathematical model for the movement of the weaving point caused by the change of the traction speed and the mandrel radius during the weaving process of the prefabricated part,and uses the constant variation method and the Euler method to analyze the weaving point prediction model.To prepare for the solution of the traction trajectory of the mandrel,it is proposed to preprocess the mandrel in STL format to convert it into an n-dimensional logic matrix,and use the parallel thinning algorithm to extract the center line of the mandrel.The extracted centerline of the mandrel is represented in the robot tool coordinate system,and the mandrel is discretized and equivalently processed.In order to satisfy the constraint condition that the center line of the mandrel with large curvature and complex mandrel satisfies the constraint condition of the vertical braiding point plane at all times during the traction process,the dynamic prediction model of braiding points solved by the constant variation method established in this paper is used to calculate the braiding feed length and knitting feed length of each discretized mandrel.The traction speed is adjusted,the posture adjustment and feed movement of the mandrel are carried out during the moving stage of the weaving point,and the traction trajectory planning for the complex mandrel with large curvature is completed to improve the weaving quality of the prefabricated part,and the experimental demonstration is carried out.The dual-machine collaborative technology is used to solve the problem of large-scale prefabricated parts traction,and the traction trajectory planning method proposed in this paper is used to calculate the traction trajectory of the master robot.According to the motion constraints of the master-slave robot,the virtual tool end is used instead of the actual clamping tool end of the slave robot to solve the problem of the slave robot.The traction trajectory is used to reduce the amount of calculation for the speed planning of the slave manipulator’s clamping tool end,and the PQArt simulation software is used for verification.Finally,the circular knitting machine and the robot traction control system are designed,the hardware is selected,the knitting motion control system based on Ether CAT is designed,and the upper computer operation interface adapted to the integrated control of the robot traction system and the knitting system is built.