Stack handling operation method, system, and computer program

Patent metadata

Field	Value
Publication number	US-9495654-B2
Application number	US-201314035384-A
Country	US
Kind code	B2
Filing date	Sep 24, 2013
Priority date	Sep 11, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A method for searching transition routes from an initial state of a plurality of stackable items to a target state by a computer at predetermined conditions includes connecting between transitionable states at an edge by a single handling operation transitioning from the initial state to the target state, to generate a state space graph; evaluating a lower bound of handling operation cost from a certain state to the target state, based on both the stacking sequence of the plurality of items in the certain state and the stacking sequence of the plurality of items in the target state; and searching a route from the initial state to the target state where the handling operation cost is minimal on the state space graph using a heuristic search algorithm based on the lower bound.

First claim

The invention claimed is:

1. A computer-implemented method for searching transition routes from an initial state of a plurality of stackable items to a target state by a computer at predetermined conditions, comprising:
receiving a current state of a plurality of stacks, wherein a stack from the plurality of stacks is used to store stackable inventory, and a state of the stacks comprises an order in which the stackable inventory is stored in the stacks;
determining a target state of the plurality of stacks based on a production schedule that is indicative of a sequence in which the stackable inventory is to be used;
identifying one or more sequences of transitionable states to rearrange the inventory according to the target state from the current state, wherein a difference between consecutive transitionable states is a single operation;
calculating an operation cost of each of the sequences of transitionable states, based on a cost associated with movement of the inventory according to the transitionable states, and by identification of a plurality of cut-positions in the current state, wherein each cut-position is indicative of a separation for a crane to operate at least once, and wherein a first cut-position from the plurality of cut-positions is identified at a first position in the initial state based on a comparison of the initial state and the target state, in response to:
the first position in the initial state holding an inventory item that exists at a first target position in the target state; and
a second position in the initial state that is adjacent to the first position holding an inventory item that does not match a corresponding adjacent position in the target state;

selecting a sequence of transitionable states to rearrange the inventory from the current state to the target state that minimizes the operation cost by using a heuristic search algorithm to minimize a number of cut-positions; and
instructing the crane to arrange the inventory according to the sequence of transitionable states selected from the one or more sequences of transitionable states.

2. The computer-implemented method of claim 1 , wherein the cost associated with movement of the inventory includes a cost of operation of the crane.

3. The computer-implemented method of claim 1 , wherein the inventory comprises manufactured products and semi-manufactured products.

4. The computer-implemented method of claim 1 , wherein the production schedule comprises a schedule to use the inventory as intake products for a plurality of industrial processes.

5. The computer-implemented method of claim 4 , further comprising receiving restriction information that restricts the movement of the inventory from one transitionable state to another transitionable state.

6. The computer-implemented method of claim 5 , wherein the restriction information specifies a limit on a weight transferable in a single operation of the crane.

7. The computer-implemented method of claim 5 , wherein the restriction information specifies a limit on a number of inventory transferable in a single operation of the crane.

8. The computer-implemented method of claim 5 , wherein the restriction information specifies a limit on a number of inventory stackable in a single stack among the plurality of stacks.

Assignees

• IBM

Inventors

• Hama Toshiyuki
• Yanagisawa Hiroki
• Yoshizumi Takayuki

Classifications

• G06Q10/063

  Operations research, analysis or management · CPC title

• G06Q10/06315 Primary

  Needs-based resource requirements planning or analysis · CPC title

• B66C23/58

  arranged to carry out a desired sequence of operations automatically, e.g. hoisting followed by luffing and slewing · CPC title

• B66C1/00

  Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles (fastening to cables or ropes F16G11/00) · CPC title