Automatic guided system and control method thereof

• US 6,493,614 B1
• Filed: 05/28/2002
• Issued: 12/10/2002
• Est. Priority Date: 12/24/2001
• Status: Expired due to Term

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jung, Sung-II
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US10/155,131
• Time in Patent Office: 196 Days
• Field of Search: 701/23, 701/69, 701/210, 701/26, 180/167, 180/168, 318/568.12
• US Class Current: 701/23
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: G05D 1/0268 using internal positioning means
• CPC Class Codes: G05D 1/0276 using signals provided by a source external to the vehicle involving a plurality of vehicles G05D1/0287; automatically controlling vehicle speed responsive to externally generated signals B60K31/0058

Abstract

An automatic guided system and control method thereof includes guide lines, stop position tags formed beside the guide lines, and an automatic guided vehicle moving along the guide lines and stopping at stop positions of the stop position tags. The automatic guided system also includes a vision unit to photograph the guide lines, a stop position detection unit to detect the stop position tags, a moving unit to drive wheels of the automatic guided vehicle, an encoding unit to detect rotation of the wheels, and a control unit to control the moving unit. The control method includes calculating first position information using a predetermined color code corresponding to a color of a second guide line and information of one of the stop position tags. The control method also includes calculating second position information using an encoder value for wheels of the automatic guided vehicle, calculating an error of position recognition using the first and second position information, and correcting the second position information.

Claims

1. An automatic guided system, comprising:

guide lines positioned along a path of movement;

stop position tags formed beside the guide lines at predetermined positions; and

an automatic guided vehicle moving along the guide lines and stopping at the predetermined positions of the stop position tags to perform work, the automatic guided vehicle including;

a vision unit to photograph the guide lines,

a stop position detection unit to detect the stop position tags,

a moving unit to drive wheels of the automatic guided vehicle to move the vehicle,

an encoding unit to detect rotation of the wheels, and

a control unit to control the moving unit in response to output data from the vision unit, the stop position detection unit, and the encoding unit.

2. The automatic guided system according to claim 1, wherein the guide lines comprise:

a first guide line divided into a plurality of zones at first regular intervals; and

a second guide line divided into a plurality of zones the same as the first guide line, each of the zones of the second guide line being divided into a plurality of differently colored sections at second regular intervals.

3. The automatic guided system according to claim 2, further comprising:

a storage unit to store predetermined color codes that correspond to a respective one of colored sections of the second guide line.

4. A method of controlling an automatic guided system, the automatic guided system having an automatic guided vehicle moving along first and second guide lines and stopping at predetermined positions of stop position tags, the first guide line divided into a plurality of zones at first regular intervals, the second guide line divided into a plurality of zones the same as the first guide line, each of the zones of the second guide line being divided into a plurality of differently colored sections at second regular intervals, the method comprising:

calculating first position information of the automatic guided vehicle using a predetermined color code corresponding to a respective one of the colored sections of the second guide line and information of one of the stop position tags;

calculating second position information using an encoder value indicative of the driving of the wheels of the automatic guided vehicle;

calculating an error of position recognition using the first and second position information; and

correcting the second position information based upon the error of position recognition.

5. The method to control the automatic guided system according to claim 4, wherein the calculating of the error of position recognition comprises:

calculating the error of position recognition using a difference between the first position information and the second position information; and

determining whether an absolute value of the error of position recognition is more than a predetermined allowable error.

6. The method to control the automatic guided system according to claim 5, wherein the correcting the second position information comprises:

correcting the second position information to correspond to the first position information if the absolute value of the error is more than the allowable error.

7. The method to control the automatic guided system according to claim 4, further comprising:

calculating first path information of the automatic guided vehicle using the first position information and the information of the one stop position tag;

calculating second path information of the automatic guided vehicle using the corrected second position information and the information of the one stop position tag; and

stopping the automatic guided vehicle at a stop position of the one stop position tag if the first path information and the second path information are equal to each other.

8. The method to control the automatic guided system according to claim 7, further comprising:

activating an alarm and stopping the automatic guided vehicle at a present position of the automatic guided vehicle if the first path information and the second path information are not equal to each other.

9. An automatic guided system having an automatic guided vehicle moving along guide lines and stopping at predetermined positions of stop positions tags, the automatic guided vehicle comprising:

a robot unit to perform work of the automatic guided vehicle;

a vision unit to photograph the guide lines;

a stop position detection unit to detect the stop position tags;

a moving unit to drive wheels of the automatic guided vehicle to move the vehicle;

an encoding unit to detect rotation of the wheels; and

a control unit to control the moving unit in response to output data from the vision unit, the stop position detection unit, and the encoding unit.

10. The automatic guided system according to claim 9, wherein the vision unit comprises:

a photographing unit to photograph the guide lines; and

an image processing unit to analyze an image photographed by the photographing unit and to output analyzed image data to the control unit.

11. The automatic guided system according to claim 9, wherein the stop position tags are formed of magnetic tapes, and the stop position detection unit includes a magnetic sensor to detect a magnetic field to detect the stop position tags.

12. The automatic guided system according to claim 9, wherein the control unit determines whether the automatic guided vehicle deviates from a path of operation, calculates an amount of deviation if the automatic guided vehicle has deviated from the path of operation, and corrects the deviation when the automatic guided vehicle arrives at a stop position.

13. The automatic guided system according to claim 9, wherein the guide lines include a first guide line divided into a plurality of zones at first regular intervals, and a second guide line divided into a plurality of zones the same as the first guide line, each of the zones of the second guide line being divided into a plurality of differently colored sections at second regular intervals.

14. The automatic guided system according to claim 13, wherein the control unit:

calculates first position of the automatic guided vehicle information using a predetermined color code corresponding to a respective one of the colored sections of the second guide line and information of one of the stop position tags,

calculates second position information automatic guided vehicle using an encoder value indicative of the driving of the wheels of the automatic guided vehicle, and

calculates an error of position recognition using the first and second position information, and corrects the second position information based on the error of position recognition.

15. The automatic guided system according to claim 14, wherein the control unit:

calculates the error of position recognition using a difference between the first position information and the second position information, and

determines whether an absolute value of the error of position recognition is more than a predetermined allowable error.

16. The automatic guided system according to claim 15, wherein the control unit corrects the second position information to correspond to the first position information if the absolute value of the error is more than the allowable error.

17. The automatic guided system according to claim 14, wherein the control unit:

calculates first path information of the automatic guided vehicle using the first position information and the information of the one stop position tag,

calculates second path information of the automatic guided vehicle using the corrected second position information and the information of the one stop position tag, and

stops the automatic guided vehicle at a stop position of the one stop position tag if the first path information and the second path information are equal to each other.