Optical guidance system for industrial vehicles

• US 4,947,094 A
• Filed: 07/23/1987
• Issued: 08/07/1990
• Est. Priority Date: 07/23/1987
• Status: Expired due to Fees

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Buck, Roger L., Dyer, Robert D., Buck, Erville C., Griffin, Jeffrey W., Lind, Michael A., Eschbach, Eugene A.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Martin, David
• Application Number:
  US07/077,701
• Time in Patent Office: 1,111 Days
• Field of Search: 180/168, 180/169, 180/167, 318/577, 318/587, 318/580, 364/424, 364/434, 364/424.01, 364/424.02, 364/424.03, 364/447, 364/449
• US Class Current: 318/587
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

An automatically guided vehicle system for steering a vehicle. Optical sensing detects an image of a segment of track mounted above the path of the vehicle. Electrical signals corresponding to the position of the track are generated. A control circuit then converts these signals into movements for the steering of the vehicle.

Claims

1. An automatically guided vehicle system comprising:

a vehicle including at least one steerable wheel;

a track mounted above said vehicle and parallel to its intended path, said track being constructed and arranged to emit light having a range of wavelengths distinct from the ambient light;

an optical system on said vehicle constructed and arranged to receive light emitted from said track and project an image of a segment of said track;

a light-sensitive device positioned to receive said image and constructed and arranged to detect the position of said image;

means for generating a first electrical signal dependent on said position;

means for converting said first electrical signal to a steering signal;

servo means for converting said steering signal into movements of said steerable wheel.

2. A system as defined in claim 1, wherein said track is reflective and is illuminated by light having said wavelengths.

3. A system as defined in claim 2, wherein said track is formed of at least two parallel sub-tracks, said sub-tracks being of different widths.

4. A system as defined in claim 2, wherein said track is longitudinally interrupted by short segments so chosen as to form a bar code.

5. A system as defined in claim 2, wherein said track is interrupted by active light-emitting elements.

6. A system as defined in claim 5, wherein said active light-emitting elements are modulated so as to transmit signals to said optical sytem.

7. A system as defined in claim 1, wherein said track is an active light-emitting elongated element.

8. A system as defined in claim 7, wherein said elongated light-emitting element is an optical wave guide receiving light having said wavelengths at one of its ends.

9. A system as defined in claim 1, wherein said optical system comprises a filter so constructed and arranged as to exclude light other than said wavelengths from said light-sensitive device.

10. A system as defined in claim 1, wherein said light-sensitive device is a linear CCD array.