Research on polychromatic sets-based assembly sequence generation method

With the increasing of the number of parts in assembly sequences generation methods based on logic reasoning, it will result in sequence combinatorial explosion. To deal with this problem, a novel sequence reasoning method combined AND-OR graph with polychromatic sets theory was presented. In this research, a novel formalization assembly model was given. Based on AND-OR graph with assembly relations, an assembly-constraint-relation matrix was constructed and a constraint-relation-logic equation was presented, which formalized the assembly conditions as location-relation-logic equation, hindrance-disassembly-relation-logic equation, junction-relation-logic equation and process constraint logic equation. In the end, a case of speed reducer was showed to demonstrate the effectivity of this method. The result shows the method can exclude the unreasonable assembly sequences in advance, reduces the solution set and decrease the computation complexity.