An integrated operation feasibility analysis method for manual assembly and disassembly in restricted space

Assembly and disassembly planning are essential parts of product design, manufacture, maintenance, and recycling, which exist through the full life cycle of products. During planning, operation feasibility must be guaranteed; otherwise, it will lead to infeasible work plan which means the actual operations cannot be completed. Especially for manual assembly and disassembly in restricted space, the operation feasibility should be considered from three respects: visibility, reachability, and geometric feasibility. And the rapid and effective feasibility analysis has extremely vital significance. However, currently the simulation method requires much manual intervention, and the geometric method focuses on assembly tools, ignoring human arm. Besides, the above three respects are always analyzed separately, which reduces the analysis efficiency. To solve these problems, this paper proposes an integrated operation feasibility analysis method, which utilizes a geometric method considering human arm to analyze visibility, reachability, and geometric feasibility together. Firstly, the simplified operation models are built to describe the assembly tool and human arm using less parameters. Secondly, two kinds of global accessibility cone with depth (GACd) are respectively constructed for the feasibility analysis of the assembly tool and the human arm. Thirdly, based on the GACds and simplified operation models, the geometric feasibility is analyzed first, and then the operation feasibility is evaluated by computing the adequacy index, reachability index, and visibility index. Finally, the proposed method is verified and discussed by the examples of simulated electronic cabin and excavator. The results show that this method is reasonable and effective in restricted space.