Research On Fuselage Docking Method And Simulation Based On 4-PPPS Parallel Mechanism

Aircraft assembly is an important part of aircraft manufacturing process,and fuselage docking is one of the main work contents of aircraft assembly.The traditional fuselage assembly method is not suitable for the requirements of high efficiency,high automation and economic benefits of modern aircraft manufacturing industry because of its low efficiency and cumbersome process.It needs to be combined with computer technology and digital positioning and measuring devices to make the aircraft assembly move towards the road of digitization and automation.Based on the fuselage attitude adjustment parallel mechanism 4-ppps,this paper analyzes its kinematics and dynamics,puts forward the attitude adjustment strategy for the automatic docking process of the front and middle fuselage according to its kinematics and dynamics characteristics,and makes an in-depth research and demonstration on the kinematics,dynamics and automatic docking process of the mechanism combined with ADAMS virtual simulation software.The main contents of this paper are as follows:The kinematics of the attitude adjustment mechanism is analyzed,the structure and degree of freedom of the mechanism are analyzed and calculated,and the position and attitude description method of the moving platform of the mechanism and the transformation relationship between different coordinate systems are described;The equations of forward and inverse position solutions of the mechanism are established,and the numerical examples of forward and inverse position solutions are compared and verified by MATLAB;It provides a theoretical basis for the calculation of driving in the process of fuselage docking.Through the dynamic analysis of the attitude adjustment mechanism,the angular velocity and acceleration of the positioner moving platform are determined,and the velocity and acceleration of the positioner moving platform and the positioner branch chain are obtained by the derivation method;Based on the results of velocity analysis,the dynamic model of attitude adjustment mechanism is established by Newton Euler method,and the dynamic equations of moving platform and branch chain are established respectively,which are solved by generalized inverse matrix;Adams and MATLAB are used to verify the correctness of the dynamic equation;It provides constraints for trajectory planning of fuselage docking process.The composition and principle of fuselage docking system are introduced in detail.The trajectory planning of fuselage docking process is carried out by using quintic polynomial,and the attitude adjustment time and the driving solution method of positioner are reasonably planned.Adams is used to simulate the rolling,pitching,deflection,position adjustment process of the middle fuselage and the automatic docking process of the front and middle fuselage to verify the correctness of the trajectory equation and attitude adjustment strategy.