Research On The Layout Optimization And Coordinated Control Of Position And Posture Adjustment System For Large Plane

Large thin-walled components have been widely used in the field of manufacturing because of their light weight and high specific strength.Large-scale plane is a common large thin-walled component.Because of its large size,small thickness and easy to produce deformation,in order to facilitate processing and transportation,large-scale plane is usually processed and transported in blocks,and then spliced and assembled after arriving at the destination.The assembling process of large-scale plane requires high accuracy,so it is necessary to adopt the pose adjustment system to realize the precise adjustment of the plane position and pose.In the process of splicing and assembling,the support layout of pose adjustment system has a great influence on the deformation of large plane.At the same time,in order to improve the efficiency of the plane splicing and realize the precise splicing between the blocks,the coordinated control of each pose adjustment mechanism in the pose adjustment system should be studied.Therefore,it is of great significance and practical value to study the layout optimization and coordinated control of large-scale plane pose adjustment system.In this paper,we focus on the following aspects of the layout optimization and coordinated control technology of the position and posture adjustment system for large plane:(1)The scheme of large plane position and attitude adjustment system is studied.According to the technical requirements of large-scale plane after position and attitude adjustment,the functions of position and attitude adjustment system are analyzed.Flatness is the key index to determine the performance of the pose adjustment system.In this paper,the influencing factors of the flatness of the plane are analyzed,and the solution method of the flatness datum plane is determined.In order to realize the accurate adjustment of large-scale plane position and attitude,this paper studies the overall scheme of large-scale plane position and attitude adjustment system.In order to reduce the influence of the support layout of parallel mechanisms on the flatness of the plane,this paper demonstrates the layout optimization scheme of multiple parallel mechanisms.Aiming at the synchronization problem of multi-parallel mechanism in coordinated motion,this paper studies the coordinated control method of multi-parallel mechanism.Aiming at the situation that the large-scale plane does not meet the flatness requirement after position and attitude adjustment,this paper studies the deformation compensation scheme.(2)The layout optimization technology of multi-parallel mechanism is studied.In order to improve the reliability of the control system,the number of parallel mechanisms should be as small as possible when the flatness requirement of the technical index is satisfied.In this paper,the optimal number of parallel mechanisms is determined according to the "N-2-1" criterion.Aiming at the problem that the support layout of multi-parallel mechanism has great influence on the flatness of the plane,this paper studies the layout optimization method based on finite element method.In order to improve the efficiency of layout optimization,this paper studies the layout optimization method which combines multiple nonlinear regression theory with genetic algorithm,because of the large amount of calculation and slow solving speed of finite element method.In this paper,the results,advantages and disadvantages of the two layout optimization methods are compared and analyzed,and their application scope is determined.(3)The coordinated control method of multi-parallel mechanism is studied.In order to ensure the synchronization of time and space in the coordinated motion of parallel mechanisms,the trajectory planning of linear motion for large-scale planes is carried out first,and then the trajectory control strategies of parallel mechanisms are determined according to the fixed constraints.In order to avoid the sticking of parallel mechanism when the electric push rod reaches the limit length,this paper calculates the change of the length of each electric push rod by inverse solution of position and attitude,and judges whether the current motion will cause the parallel mechanism to stick.In order to verify whether the coordinated control algorithm can meet the synchronization requirement,the dynamic simulation model of plane and multi-parallel mechanism is established in Simulink to simulate the process of arbitrary spatial motion of the system,and its trajectory is analyzed.(4)An experimental study on the position and attitude adjustment system of large plane is carried out.In order to ensure the reliability of the large-scale plane position and attitude adjustment system in actual work,it is necessary to carry out experimental research.In this paper,a test system is developed,and the composition and function of the test system are described.In order to verify whether the positioning accuracy of parallel mechanism in steady state can meet its technical specifications,the positioning accuracy test of parallel mechanism is carried out in this paper.In order to verify whether the coordinated control algorithm designed in this paper meets the design requirements,the pose adjustment verification experiment is carried out.The performance of the coordinated control algorithm is evaluated by the position,flatness and pointing accuracy of the plane reaching the target pose.In order to make the flatness of the plane meet the technical requirements,this paper studies the deformation compensation technology and carries out the deformation compensation experiment.