| The development of virtual assembly technology provides a new idea for the overallassembly process design of aerospace products. Introducing virtual human in assemblysimulation, the immersive and reality will be enhanced, and product structure and assemblyprocess can also be optimized based on the analysis results of ergonomics.When designing assembly simulation in existing simulation softwares, the designer mustmanually adjust a lot of joint angles to create a human posture. The complexity of humanbody and assembly activity makes this process very cumbersome. In addition, designer’s sightcan easily be blocked by other parts because the assembly environment of aerospace productsis often complex, which makes manual posture adjustment more difficult to achieve.In order to improve the efficiency of human action design, this thesis presents a methodbased on assembly operation action library. In order to build the action library, firstly, inversekinematics algorithms are studied. Based on the analysis and comparison of the existingalgorithms, the Forward And Backward Reaching Inverse Kinematics (FABRIK) algorithm isimproved and an obstacle-avoiding FABRIK algorithm is put forward. Then, a new methodwhich is used to plan collision-free grasping actions of virtual human for assembly process ofaerospace products is presented. This method uses obstacle-avoiding FABRIK algorithm todesign a collision-free grasping posture, and then it uses Bidirectional Rapidly-exploringRandom Tree (Bi-RRT) algorithm to plan the motion of human arm from a given initialposture to the grasping posture.Based on the above study, some parametric action design approaches are developed andan assembly operation action library is built on the platform of Tecnomatix/Process Simulate9.0. The function of action library is verified with some case studies. Experimental resultsshow that the assembly operation action library can help to improve the design efficiency ofassembly simulation. |
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