On Further Reduction of Constraints in “Nonpure Petri Net Supervisors for Optimal Deadlock Control of Flexible Manufacturing Systems”

The above paper proposes a method to design optimal control places with self-loops for flexible manufacturing systems by solving an integer linear programming problem (ILPP) at each iteration. However, some constraints in the ILPP are redundant. This technical correspondence shows that they can be removed without changing the feasible region of the ILPP.