Planning And Experimental Study Of Cabin Docking Based On 6-SOF Parallel Mechanism

The docking of cabin assembly is an important part to ensure the accuracy and stability of aerospace product manufacturing.The traditional docking method uses analog coordination,special fixtures and manual to execute docking assembly.This docking method has some shortcomings,such as poor consistency,low precision,high labor intensity and low efficiency.In this thesis,six-degree-of-freedom parallel mechanism is used to realize automatic docking of large cabins,and advanced digital quantity coordination,flexible assembly and automatic docking assembly technology are studied.The main contents include the non-singular path planning of 6-DOF parallel mechanism,the control strategy of non-dynamic model and the design and execution of docking test.The cabin automatic docking system includes the measurement and fitting subsystem,the docking control subsystem and the docking execution subsystem.The process of automatic docking,the main functions of each subsystem and the relationship between them are described.The distribution of inverse Jacobian matrix of 6-DOF parallel mechanism in sixdimensional space is analyzed,and the boundary between singular and non-singular regions is delineated in its workspace.Then the non-singular path planning is carried out by using B-spline curve.At the same time,the electric cylinder jerk,the 6-DOF parallel mechanism operability and the path time are taken as optimization goal.The PAMOPSO algorithm is used to iteratively optimize the path to obtain the Pareto solution set.Without modeling the precise electrodynamic modeling of the electric cylinder,the improved fuzzy neural network is used to dynamically modify the parameters of the PID controller to control it,and the simulation control is carried out on the mathematical model of the electric cylinder.The accuracy and stability are verified by lateral comparison with other control methods.Finally,the artificial fish swarm algorithm is used to optimize the initial parameters of the fuzzy neural network to obtain better accuracy.Using the existing 6-DOF parallel mechanism,model cabin and other auxiliary equipment,a test platform for automatic docking of cabin sections is built,and the test flow and pose conversion algorithm are designed.The displacement and Euler angle of the movement required by the 6-DOF parallel mechanism when the docking of two cabins is completed are solved.Finally,the data is used to drive the parallel mechanism to complete the docking test.