CARRIER

• US 20130204482A1
• Filed: 12/10/2012
• Published: 08/08/2013
• Est. Priority Date: 02/08/2012
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: SUYAMA, Norihiko
• Granted Patent: US 9,062,975 B2
• Time in Patent Office: Days
• US Class Current: 701/28
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

A carrier which automatically travels on a pathway. A carrier comprising: a carrier main body which travels on the pathway including a first area and a second area other than the first area; a distance measuring sensor which is provided in the carrier main body, measures an intensity of reflected light a plurality of times, and obtains a plurality of pieces of measured data; a map data storage unit which stores map data in which structures provided along the pathway are recorded; an approximate line calculation unit which calculates an approximate line based on a set of pieces of measured data having the light intensity equal to or more than a predetermined threshold among the plurality of pieces of measured data in the first area and calculates the approximate line based on the set of the plurality of pieces of measured data in the second area; and a position calculation unit which calculates a position of the carrier main body by collating the approximate line and the map data.

Claims

1. A carrier which automatically travels on a pathway, comprising:

a carrier main body which travels on the pathway including a first area and a second area other than the first area;

a distance measuring sensor which is provided in the carrier main body, measures an intensity of reflected light a plurality of times, and obtains a plurality of pieces of measured data;

a map data storage unit which stores map data in which structures provided along the pathway are recorded;

an approximate line calculation unit which calculates an approximate line based on a set of pieces of measured data having the light intensity equal to or more than a predetermined threshold among the plurality of pieces of measured data in the first area and calculates the approximate line based on the set of the plurality of pieces of measured data in the second area; and

a position calculation unit which calculates a position of the carrier main body by collating the approximate line and the map data.

2. The carrier according to claim 1, further comprising:

a traveling motor which imparts driving force to traveling wheels and enables the carrier main body to travel; and

a travel control unit which controls the traveling motor based on a given travel command and the calculated current position.

3. The carrier according to claim 1,

wherein the set of the pieces of measured data having the light intensity equal to or more than the predetermined threshold includes a plurality of small sets which are separated from one another, and at least one of the measured data is included in each small set.

4. The carrier according to claim 3,

wherein the approximate line calculation unit calculates the approximate line while having the plurality of small sets which are separated from one another as one set.

5. The carrier according to claim 1,

wherein a plurality of the structures in the first area are provided along the pathway, and a reflecting plate which reflects light with an intensity equal to or more than the predetermined threshold is provided on each structure.

6. The carrier according to claim 5,

wherein a rack is provided along the pathway in the first area, and the reflecting plate is provided in a column of the rack.

7. The carrier according to claim 6,

wherein the approximate line calculation unit calculates one approximate line based on the measured data from a plurality of the reflecting plates which are arranged on the column of the rack provided along the pathway.

8. The carrier according to claim 5,

wherein the reflecting plate is provided only on a surface opposite to the first area of the structure.

9. A position calculation method of a carrier which automatically travels on a pathway, comprising:

a step of traveling the pathway including a first area and a second area other than the first area;

a step of measuring an intensity of reflected light a plurality of times by a distance measuring sensor provided in a carrier main body and obtaining a plurality of pieces of measured data;

a step of storing map data in which a structure provided along the pathway is recorded;

a step of calculating an approximate line based on a set of pieces of measured data having light intensity equal to or more than a predetermined threshold among the plurality of pieces of measured data in the first area and calculating the approximate line based on the set of the plurality of pieces of measured data in the second area; and

a step of calculating the position of the carrier main body by collating the approximate line and the map data.