The selection of the control unit optimal signalling sequence in containers stack handling at sea port terminal

Abstract

The possibility of increasing the productivity of technological operations performed in the storage area of a container terminal due to the introduction of automation elements into mechanized warehouse cargo handling has been researched. As one of the possible automation options, a method for transporting and storing containers with the implementation of a loader control unit in the form of a deterministic finite automaton is proposed. The sequence of actions of the loader is simulated in the control unit by a line of encoded symbols generated by the transition diagram of the Mealy automaton. In this case, the transition diagram is an automatic programming tool allowed mathematically describing the logic of controlling the actions of the loader when it processes a stack of containers. As a result of generation at the output of the machine, several valid loader control lines are got. Each symbol of the control line corresponds to one action from the loader working cycle. It is required to find the control line that will bring the loader to the state, when the picking up of containers from the stack is completed, in the minimum number of actions. The object of the research is a variable sequence of loader actions during partial disassembly of the stack with its corresponding control line. To reduce the complexity of the task being solved, each control line is divided into sections consisting of symbols responsible for the following actions of the loader: moving when changing the disassembled row, disassembling the row with the picking up and movement of target containers, returning blocking containers to the stacks where they were initially placed. As a result of the comparison of the corresponding symbolic sections of different lines, an algorithm that allows choosing the optimal sequence of signals for the control unit of the technological automaton in terms of the number of symbols is developed.