Automatic guidance system for moving objects

• US 4,049,961 A
• Filed: 01/30/1975
• Issued: 09/20/1977
• Est. Priority Date: 02/01/1974
• Status: Expired due to Term

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Marcy, Raymond
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Moore, David K.
• Application Number:
  US05/545,749
• Time in Patent Office: 964 Days
• Field of Search: 250/202, 250/222, 250/578, 250/216, 250/215, 180/79.1, 180/98
• US Class Current: 250/202
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S

Abstract

An automatic system for guiding moving objects is described which cooperates with passive responders situated on or along the road on which the system operates. The part of the system which is located aboard a vehicle comprises one or two optical transmitter/receiver units. The transmitter, comprising an emitter diode or two such diodes energized either continuously or alternately, emits a light signal in the form of a beam of radiation of limited dimensions covering a certain number of responders, which reflect a fraction of the light reaching them. The received signals make it possible to form an electrical signal whose amplitude and sign are a function of the position of the transmitter along an axis transverse to a longitudinal reference axis. This system is applicable to the automatic guidance of moving objects such as road vehicles along routes marked by responders.

Claims

1. A system for the automatic guidance of a movable object traveling over a supporting surface along a predetermined path, comprising:

transmitting means on said object for directing radiant energy forwardly and sideways toward said surface in the form of at least one pair of beams intersecting said surface in two substantially rectangular zones of illumination with substantially coextensive major dimensions in the direction of motion of said object, said zones being relatively offset transversely to said direction of motion and lying alongside a centerline of said path;

a series of spaced-apart responders disposed in at least one row parallel to said centerline and close to said surface for reflecting radiant energy of substantially equal intensity from both said beams toward said object as long as said object occupies a normal position athwart said centerline, said zones having a width exceeding that of said row and a length extending over a plurality of responders of said row;

receiving means on said object for separately detecting the reflections of said beams from said responders; and

steering-control means on said object connected to said receiving means for correcting deviations from said centerline, said receiving means including comparison means for ascertaining differences indicative of said deviations between the intensities of said reflections.

2. A system as defined in claim 1 wherein said transmitting and receiving means include respective laser diodes.

3. A system as defined in claim 2, further comprising semitransparent shield means between said transmitting and receiving means.

4. A system as defined in claim 1 wherein said transmitting means comprises a pair of transmitters radiating toward opposite sides of said object for locating said zones on opposite sides of said centerline in said normal position, said responders being disposed in two rows symmetrically spaced from said centerline.

5. A system as defined in claim 1 wherein said path is one of two intersecting roadways provided with rows of responders for the guidance of respective objects traveling therealong, the width of said zones being less than the spacing of said responders in a row whereby an object passing the intersection on one roadway remains unaffected by the responders of the other roadway.

6. A system as defined in claim 1 wherein said receiving means includes a first receiver, with a field of detection extending over substantially the entire length of said zones for actuating said steering-control means in response to reflections from any of said plurality of responders, and a second receiver with a field of detection extending over a fraction of said length for picking up reflections from only one responder at a time, further comprising speed-control means connected to said second receiver for varying the velocity of said object in accordance with the spacing of said responders.

7. A system as defined in claim 6 wherein the responders coacting with said second receiver are disposed alongside said path at an elevation above said surface.

8. A system as defined in claim 1 wherein said transmitting means comprises a pair of transmitters radiating toward one side of said object for locating said zones in relatively offset relationship overlapping on said row in said normal position, said beams having characteristic parameters facilitating separate detection of their reflections by said receiving means.

9. A system as defined in claim 8 wherein said characteristic parameters are relatively inverted phases, said transmitting means including a sine-wave generator for modulating said beams in mutual phase opposition.

10. A system as defined in claim 8 wherein said characteristic parameters are different wavelengths.

11. A system as defined in claim 8 wherein said characteristic parameters are different modes of polarization.

12. A system as defined in claim 8 wherein said pair of transmitters are part of one of two substantially identical transmit-receive units disposed on opposite sides of said object for radiating respective pairs of relatively offset beams toward opposite sides of said centerline and detecting reflections thereof, the zones of illumination produced by said pairs of beams overlapping on respective rows of responders in said normal position.

13. A system as defined in claim 12 wherein said path splits into two diverging branches, each of said rows of responders continuing into one of said branches, the transmit-receive units on either side of said object being selectively deactivable for guiding said object exclusively by the row of responders on the opposite side onto a respective branch.