Research On Trajectory Planning Of Four-axis Winding Machine Based On Spatial Curve Characteristic Function Sampling And Envelope Body Algorithm

Owing to the characteristics of light weight,high strength,corrosion resistance and strong designability,Filament reinforced composite products are widely used in aerospace,shipbuilding,military industry,petrochemical industry,automobile industry and other fields.Filament winding machine,one of the core equipment to produce filament reinforced composite products,produces filament reinforced composite products by winding the filament reinforced composite materials on the surface of the smooth connection combined revolving body,according to a certain filament winding law.Therefore,the filament winding law and the movement trajectory of Filament winding machine according to the law become the key point of filament winding forming technology.Accordingly,the sampling algorithm of doffing point trajectory for filament winding law and the motion trajectory planning algorithm for filament winding machine have become the research hotspot of many experts and scholars.The common sampling algorithms of doffing point trajectory can be divided into equal parameter sampling algorithm and equal arc length sampling algorithm.And these two algorithms are divided into equal parts to select sampling points without considering the change of doffing point trajectory curve shape,which leads to the low quality of the doffing points and the need to set the number of points in advance.The common trajectory planning algorithms of four-axis winding machine include fixed doffing angle and fixed suspension line length motion trajectory planning algorithms.Although these algorithms can plan the four-axis winding machine trajectory accurately,they can't constrain the motion of the feed eye within a certain range and don't plan the speed of the motion trajectory,which may cause the problem that the motion of the feed eye may exceed the operation range of the four-axis winding machine and the winding machine runs unsteadily.Therefore,the sampling algorithms of doffing point and the motion trajectory algorithm of the four-axis winding machine need to be further studied.In view of the low quality of the common sampling algorithm of doffing points,this paper studies and proposes the sampling algorithm based on the characteristic function of spatial curve.The sampling point is selected by establishing the characteristic function of the spatial curve,which improves the quality of the sampling of the doffing point trajectory and the accuracy of the filament reinforced composite products which produced by the four-axis winding machine.In order to solve the problem that the common sampling algorithm of doffing points needs to set the number of points in advance,this paper further improves the sampling algorithm based on the spatial curve characteristic function,dividing the sampling points into feature points and auxiliary points,and adding the maximum absolute error as the termination condition.An adaptive sampling algorithm base on the space curve characteristic function is proposed,which improves the capture of the curve shape of the doffing point trajectory and adaptively determines the number of sampling points according to the termination condition.In view of the shortcomings of common four axis winding machine trajectory planning algorithms,this paper studies and proposes a four-axis winding machine motion algorithm and a four-axis winding machine speed planning algorithm based on the envelope algorithm.The four-axis winding machine trajectory planning algorithm based on envelope algorithm constrains the trajectory of the feed eye on the contour line of the envelope body,preventing the motion trajectory of the feed eye from exceeding the operation range of the four-axis winding machine and the collision between the four-axis winding machine and the surrounding equipment.The speed planning algorithm of the fouraxis winding machine constrains the four-axis winding machine by establishing a linear planning model based on the optimal time to ensure the stable operation of the four-axis winding machine and improve the processing efficiency of the four-axis winding machine.In order to verify the correctness and feasibility of the doffing point trajectory sampling algorithm and four-axis winding machine trajectory planning algorithm studied in this paper,the researched algorithm is implemented with code and winding experiment is carried out on the four-axis winding machine.The experimental results show that the algorithm proposed in this paper can be applied to the four-axis winding machine to achieve winding forming,improving the accuracy of the four axis winding machine to produce filament reinforced composite products,preventing the interference between the feed eye and the surrounding equipment,ensuring the stable operation of the four-axis winding machine,and making up for the shortcomings of the common doffing point sampling algorithm and the four-axis winding machine trajectory planning algorithm.