Stack handling operation method, system, and computer program

• US 9,495,653 B2
• Filed: 08/29/2013
• Issued: 11/15/2016
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hama, Toshiyuki, Yanagisawa, Hiroki, Yoshizumi, Takayuki
• Primary Examiner(s): Coupe, Anita
• Assistant Examiner(s): Divelbiss, Matthew H
• Application Number:
  US14/013,605
• Publication Number:
  US 20140074541A1
• Time in Patent Office: 1,174 Days
• US Class Current: 1/1
• CPC Class Codes: B66C 1/00 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 Class Codes: B66C 23/58 arranged to carry out a desired sequence of operations automatically, e.g. hoisting followed by luffing and slewing
• CPC Class Codes: G06Q 10/063 Operations research, analysis or management
• CPC Class Codes: G06Q 10/06315 Needs-based resource requirements planning or analysis

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.

Claims

1. A system comprising:

a crane; and

a computer configured to;

receive 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;

determine 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;

identify 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;

calculate 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 based on a comparison of the current state and the target state, wherein each cut-position is indicative of a separation for the 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 current state in response to;

the first position in the current state holding an inventory item that exists at a first target position in the target state; and

a second position in the current state, which is adjacent to the first position, holding an inventory item that does not match a corresponding adjacent position in the target state;

select 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

instruct 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 system of claim 1, wherein the cost associated with movement of the inventory includes a cost of operation of the crane.

3. The system of claim 2, wherein the inventory comprises manufactured products and semi-manufactured products.

4. The system 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 system of claim 4, wherein the computer is further configured to receive restriction information that restricts the movement of the inventory from one transitionable state to another transitionable state.

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

7. The system 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 system 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.

9. An apparatus comprising:

an interface to communicate with a crane; and

a processor configured to;

receive a current state of a plurality of stacks, wherein a stack from the plurality of stacks is used to store stackable items, and a state of the stacks comprises an order in which the items are stacked in the stacks;

determine a target state of the plurality of stacks;

identify one or more sequences of transitionable states to rearrange the items according to the target state from the current state;

calculate an operation cost of each of the sequences of transitionable states, by identification of a plurality of cut-positions in the current state based on a comparison of the current state and the target state, wherein each cut-position is indicative of a separation for the 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 current state in response to;

the first position in the current state holding an inventory item that exists at a first target position in the target state; and

a second position in the current state, which is adjacent to the first position, holding an inventory item that does not match an inventory item at a corresponding position that is adjacent to the first target position in the target state;

select a sequence of transitionable states to arrange the items from the current state to the target state that minimizes the operation cost by minimization of a number of cut-positions; and

instruct the crane, via the interface, to arrange the items according to the sequence of transitionable states selected from the one or more sequences of transitionable states.

10. The apparatus of claim 9, wherein the target state is based on a production schedule that is indicative of a sequence in which the items are to be used.

11. The apparatus of claim 9, wherein a difference between consecutive transitionable states is a single operation.

12. The apparatus of claim 9, wherein the items are steel products after a steel manufacturing process and before a hot rolling process, the current state is a stacking state of the steel products after the steel manufacturing process, and the target state is the stacking state of the steel products suitable for the hot rolling process.

13. The apparatus of claim 9, wherein the processor is further configured to communicate the operation cost to a steel production scheduler in response to receipt of the current state and the target state from the production scheduler.