Research On The Theory And Method Of High-Speed And Stable Running Of The Feeding System In The Auto-Body-Out-Panel Stamping Line

As the project of the high-grade CNC machine tools and basic manufacturing equipment is proposed,implemented,and promoted,the leaping development of the auto-body-out-panel stamping line has been realized.It not only accords with the development direction of high speed,flexibility,automation,and intelligence in the automobile industry,but also meets the growing needs of the automobile industry.Various types of stamping lines,which include the stamping line of the large-scale mechanical press,the stamping line of the large-scale servo press,and the stamping line of the large-scale multiple stations,have been developed by domestic manufactures.And they have been sold into well-known domestic and foreign automobile companies,such as FAW,SAIC,Great Wall,BYD,GM,PSA,Ford,and so on However,there are still some problems in this field,such as insufficient research depth of general technologies and insufficient verification of theoretical results,which seriously restrict further development of the auto-body-out-panel stamping line.The auto-body-out-panel stamping line can transform sheet metals into various complex automobile outer panels by several feeding systems and stamping stations.Due to the technical barrier,data security,and other reasons,there are a few public types of research in the field.However,relevant research data indicate that the type and trajectory of the feeding system have a large effect on the stability of the high-speed auto-body-out-panel stamping line.Without consuming any actual production resources,the simulation technology of the auto-body-out-panel stamping line can dynamically simulate the actual production process,quickly verify the rationality and effective ness of the result for the trajectory planning of the manipulator or multi-machine coordination,and shorten the development period.Therefore,this paper will systematically study the structure and its trajectory of the feeding system in the auto-body-out-panel stamping line from theoretical analysis,simulation optimization,and experimental verification.From the perspective of graph theory,the theory of isomorphism identification and automatic sketching in the planar kinematic chain has been studied.Compared with common methods of isomorphism identification and automatic sketching respectively,a simple and reliable method suitable for isomorphism identification and automatic sketching in the planar kinematic chain is proposed.On the basis of the link-link adjacency matrix,loop theory,and the characteristic that links and kinematic pairs are connected alternatively,the relation between the planar kinematic chain and the pseudo-loop matrix is established.The criterion of isomorphism identification in the planar kinematic chain is also clearly defined.Based on the distribution characteristic and connection relation between links and kinematic pairs in the planar kinematic chain,link-assortment principles of the automatic sketching of the planar kinematic chain are summarized.Combined with the concentric circle and the cross-product operation,the route of the automatic sketching of the planar kinematic chain is further introduced.Results of the theoretical analysis show that the method of isomorphism identification based on the pseudo-loop matrix can effectively distinguish the isomorphism between kinematic chains,and the link assortment of the optimal layout can also automatically sketch the planar kinematic chain in the graphical form.Based on the relation of links and kinematic pairs in the planar kinematic chain,the link assortment under the number of links and the number of the degree of freedom is derived.Based on the link-link adjacency matrix,the link-path adjacency matrix is proposed to intuitively reflect the distribution of links and loops in the planar kinematic chain.The characteristics of the classic method of structural synthesis in the planar kinematic chain are studied.By deriving the link assortment set,establishing the element database,ensuring element position,selecting elements from the element database,detecting the rigid chain,identifying the isomorphism,and automatic sketching,based on the ink-path adjacency matrix,this paper proposes the method of structural synthesis for the planar kinematic chain wth pure rotary pairs.Under the requirements of the working environment and expected functions for the feeding system in the auto-body-out-panel stamping line,based on the results of structural synthesis for the planar kinematic chain with pure rotary pairs,the mechanism of the feeding system is created innovatively by transforming several rotary pairs into prismatic pairs in the result of structural synthesis for the planar kinematic chain with pure rotary pairs.Therefore,the whole innovative design method of the task-driven mechanism is presented.The results of the theoretical analysis show that the proposed method of structural synthesis can generate the whole family mechanisms of the planar kinematic chain and the proposed innovative design method of the task-driven mechanism in this paper can effectively design a new type of feeding system They lay a foundation for the high-speed auto-body-out-panel stamping line under the low vibration.The common methods for the establishment of the robotic kinematic model are studied.Based on the method of Denavit-Hartenberg,the formula suitable for the rapid establishment of the kinematic model of the planar manipulator is derived.After analyzing the solving characteristics of the robotic inverse kinematics and working characteristics of the feeding system,combined with the particle swarm optimization algorithm and Lagrangian dynamics,a method based on improved particle swarm optimization algorithm and joint classification is proposed to obtain solutions in the inverse kinematics.Analyze the bottleneck factors related to the vibration and stamping per minute of the manipulator in the auto-body-out-panel stamping line.From the perspective of the trajectory planning,the trajectories in the joint space and the Cartesian space are fitted by the quintic B-spline curve.Meanwhile,the weighting method is employed to reduce the jerk of the trajectories of the redundant manipulator in the joint space and the Cartesian space.By properly coordinating the torques of servo motors corresponding to all active joints,the manipulator can run at a high speed and low vibration Experimental results show that the proposed method of trajectory planning can significantly improve the working performance of the manipulator.The working flow of the auto-body-out-panel stamping line is studied.After the connection between the three-dimensonal model in Solid Works and the two-dimensional model in MATLAB is established,the two-dimensional modeling technology of rapid establishment based on the product model is proposed to generate the accurate model of the simulation system in the auto-body-out-panel stamping line.The bottleneck factors that restrict the high-speed and stable running of the auto-body-out-panel stamping line are studied.By adjusting the running period and phase difference between different types of motion equipment,the decomposition planning method of multi-machine coordination based on the phase delay and period adjustment is proposed to ensure that all motion equipment runs continuously in the auto-body-out-panel stamping line.The three-dimensional model in SolidWorks and the results of multi-machine coordination are imported into ADAMS and verified by simulation in turn.Simulation results show that the poses of models in different simulation software are kept consistent at any time,and the proposed method can effectively increase the stamping per minute of the auto-body-out-panel stamping line.