Optically based position location system for an autonomous guided vehicle

• US 5,812,267 A
• Filed: 07/10/1996
• Issued: 09/22/1998
• Est. Priority Date: 07/10/1996
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Holland, John M., Inderieden, Rebecca S., Tran, Theresa T., Everett, Hobart R. Jr., Gilbreath, Gary A.
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Smith, Zandra V.
• Application Number:
  US08/677,745
• Time in Patent Office: 804 Days
• Field of Search: 356/375, 356/141.1, 250/206.1, 250/225, 381/577, 381/580, 381/587, 180/167, 180/169
• US Class Current: 356/614
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

An optically based position location system, comprises multiple reflectorsositioned at known locations in an environment; a vehicle for traveling along a path in the environment; a first sensor for generating and detecting a collimated and polarized first light signal reflected from one of the reflectors, and for generating a first output signal in response to detecting the first light signal; a second sensor for generating and detecting a collimated and polarized second light signal reflected from the reflector reflecting the first light signal, and for generating a second output signal in response to detecting the second light signal; and a data processor which uses the first and second output signals for determining the distance between a reference coordinate on the vehicle and the reflector.

Claims

1. An optically based position location systems comprising:

multiple reflectors positioned at known locations in an environment;

a vehicle for traveling along a path in said environment;

a first sensor for generating and detecting a collimated and polarized first light signal reflected from one of said reflectors, and for generating a first output signal in response to detecting said first light signal,

a second sensor for generating and detecting a collimated and polarized second light signal reflected from said one reflector, and for generating a second output signal in response to detecting said second light signal where said first and second sensors are mounted on said vehicle so that said first and second light signals converge and

a first data processor for determining the distance between a reference coordinate on said vehicle and said one reflector based on said first and second output signals.

2. The optically based location system of claim 1 in which said first and second light signals converge at a point which is at a fixed distance from said reference coordinate.

3. The optically based location system of claim 1 in which said vehicle travels in a path supervised by a second data processor which provides path planning control signals to said first data processor.

4. The optically based location system of claim 3 in which said first data processor is mounted to said vehicle.

5. The optically based position location system of claim 1 in which said reflectors are retroreflectors.

6. An optically based position location system, comprising:

multiple reflectors positioned at known locations in an environment;

a vehicle for traveling along a path in said environment;

a first sensor for generating and detecting a collimated and polarized first light signal reflected from one of said reflectors, and for generating a first output signal in response to detecting said first light signal;

a second sensor for generating and detecting a collimated and polarized second light signal reflected from said reflector reflecting said first light signal, and for generating a second output signal in response to detecting said second light signal;

a third sensor for generating and detecting a collimated and polarized third light signal reflected from one of said reflectors, and for generating a third output signal in response to detecting said first light signal;

a fourth sensor for generating and detecting a collimated and polarized fourth light signal reflected from said reflector reflecting said third light signal, and for generating a fourth output signal in response to detecting said fourth light signal;

a first data processor for determining the distance between a reference coordinate on said vehicle and said reflector reflecting either said first and second light signals or said second and third light signals, from said first, second, third, and fourth output signals.

7. The optically based position location system of claim 6 in which said reflectors are retroreflectors.

8. The optically based location system of claim 6 in which said first and second sensors are mounted on said vehicle so that said first and second light signals converge.

9. The optically based location system of claim 8 in which said first and second light signals converge at a point which is at a fixed distance from said reference coordinate.

10. The optically based location system of claim 8 in which said vehicle travels in a path supervised by a second data processor which provides path planning control signals to said first data processor.

11. The optically based location system of claim 8 in which said first data processor is mounted to said vehicle.