Work transfer system, route setting method, and route setting program

• US 7,801,641 B2
• Filed: 02/10/2006
• Issued: 09/21/2010
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Hirata Corporation
• Original Assignee: Hirata Corporation, Hirata Software Technology Co., Ltd.
• Inventors: Kandabashi, Tsugumitsu, Uchimura, Keiichi, Hu, Zhencheng, Yoshikawa, Takeru
• Primary Examiner(s): Kasenge; Charles R
• Application Number:
  US11/919,981
• Publication Number:
  US 20090099686A1
• Time in Patent Office: 1,684 Days
• Field of Search: 700/97, 700 99-102, 700/112, 700/113, 700/213, 700/214, 700/228, 700/230, 414/222.01, 414/935, 414/940
• US Class Current: 700/228
• CPC Class Codes: B65G 1/0478 for matrix-arrangements
• CPC Class Codes: B65G 37/02 Flow-sheets for conveyor combinations in warehouses, magazines or workshops
• CPC Class Codes: B65G 43/10 Sequence control of conveyors operating in combination
• CPC Class Codes: G05B 19/41895 using automatic guided vehicles [AGV] control of position or course of AGV's G05D1/00
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y02P 90/60 Electric or hybrid propulsion means for production processes
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling

Abstract

A route setting method according to the present invention sets, in a work transfer system including a plurality of work transfer units which connect a plurality of loading places to a plurality of unloading places, a route of the work transfer units to pass a work between a planned loading place and a planned unloading place which are required to transfer the work in the plurality of loading places and the plurality of unloading places. The route setting method includes the steps of setting, based on layout information representing a layout of the plurality of work transfer units, a plurality of candidates of the route between the planned loading place and the planned unloading place, and selecting, based on a predetermined condition, one route from the plurality of candidates of the route set in the candidate setting step.

Claims

1. A work transfer system including a plurality of work transfer units which connect a plurality of loading places to a plurality of unloading places, the system comprising:

a layout information database which stores layout information representing a layout of the plurality of work transfer units; and

route setting means implemented within a computer for setting, based on the layout information, a route of the work transfer units to pass a work between a planned loading place and a planned unloading place which are required to transfer the work in the plurality of loading places and the plurality of unloading places,

wherein the plurality of work transfer units are constituted from a plurality of first work transfer units which transfer the work in one direction and a plurality of second work transfer units capable of changing a work transfer direction, the first and second work transfer units transferring the work by receiving and sending the work between two adjacent work transfer units,

said route setting means comprising;

candidate setting means for setting a plurality of candidates of the route between the planned loading place and the planned unloading place; and

route selection means for selecting, based on a predetermined condition, one route from the plurality of candidates of the route set by said candidate setting means, said route selection means calculating a route selection evaluated value by

Route selection evaluated value={2/(1+e<sup>−

a(Tw/Tnw−

1)</sup>)}−

1

where Tnw is a transfer time without interference with another work, Tw is a transfer time including the wait time for avoiding interference with another work which has an already set route, and a is a slope of a sigmoid function; and

said candidate setting means sets, as a via point, each of the plurality of work transfer units capable of passing the work between the planned loading place and the planned unloading place and sets a shortest route as the candidate of the route for each via point.

2. The work transfer system according to claim 1, characterized by further comprising determination means for determining whether to start transferring the work at a planned transfer start time through the route set by said route setting means, wherein

said determination means sets transfer start when the route selection evaluated value of the route set by said route setting means is not larger than a predetermined value and sets transfer wait when the route selection evaluated value of the route set by said route setting means is larger than the predetermined value.

3. The work transfer system according to claim 1, further comprising a database which stores, for each work whose route is set by said route setting means, a planned transfer start time of the work and a planned passage time of the work in each of the work transfer units on the route.

4. A route setting method of, in a work transfer system including a plurality of work transfer units which connect a plurality of loading places to a plurality of unloading places, setting a route of the work transfer units to pass a work between a planned loading place and a planned unloading place which are required to transfer the work in the plurality of loading places and the plurality of unloading places, the plurality of work transfer units being constituted from a plurality of first work transfer units which transfer the work in one direction and a plurality of second work transfer units capable of changing a work transfer direction, the first and second work transfer units transferring the work by receiving and sending the work between two adjacent work transfer units, the method comprising the steps of:

setting, in a computer, based on layout information representing a layout of the plurality of work transfer units, a plurality of candidates of the route between the planned loading place and the planned unloading place; and

selecting, in a computer, based on a predetermined condition, one route from the plurality of candidates of the route set in the candidate setting step,

said route selection means calculating a route selection evaluated value by;

Route selection evaluated value={2/(1+e<sup>−

a(Tw/Tnw−

1)</sup>)}−

1

where Tnw is a transfer time without interference with another work, Tw is a transfer time including the wait time for avoiding interference with another work which has an already set route, and a is a slope of a sigmoid function,

wherein in the candidate setting step, each of the plurality of work transfer units capable of passing the work between the planned loading place and the planned unloading place is set as a via point, and a shortest route is set as the candidate of the route for each via point.