Method and a device for laser optical navigation

• US 5,241,481 A
• Filed: 08/21/1990
• Issued: 08/31/1993
• Est. Priority Date: 06/22/1987
• Status: Expired due to Fees

• Current Assignee: Arnex Handelsbolag
• Original Assignee: Arnex Handelsbolag
• Inventors: Olsen, Bengt O.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US07/570,960
• Time in Patent Office: 1,106 Days
• Field of Search: 364/424.01, 364/424.02, 364/449, 364/456, 364/460, 364/513, 364/443, 364/444
• US Class Current: 701/207
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S

Abstract

A laser-optical navigation method and apparatus are provided for rotationally emitting a pulsed beam of light from a transmitter/sensor unit mounted on a vehicle. Ground mounted reflectors in the path of the emitted light reflect the light back to the transmitter/sensor unit, which converts the reflected light to electrical signals. Attitude angles and other directional and locational information are computed from these signals, which may be used to navigate the vehicle.

Claims

1. A laser-optical method for navigating a vehicle comprising:

a) providing a transmitter/sensor unit mounted on said vehicle for transmission of a beam of light and reception of reflected light, and a plurality of spaced-apart reflectors positioned a distance away from said transmitter/sensor unit for reflecting said beam of light;

b) transmitting said beam of light away from said transmitter/sensor unit toward one of said reflectors;

c) reflecting said beam of light off said one of said reflectors back toward said transmitter/sensor unit;

d) receiving said reflected light with said transmitter/sensor unit;

e) measuring an elevation angle of said vehicle from said reflected light;

f) measuring an azimuth angle of said vehicle from said reflected light;

g) repeating steps c)-g) for each of said plurality of reflectors;

h) compiling said measured elevation angles and azimuth angles; and

i) computing navigational data elements for said vehicle from said compiled elevation and azimuth angles, said elements comprising a position in three-dimensional coordinates, a heading, a pitch angle, and a roll angle, and wherein said elements may be used to navigate said vehicle.

2. The method of claim 1 wherein said beam of light is pulsed.

3. The method of claim 1 wherein said beam of light is in a shape of a vertical fan.

4. The method of claim 1 further comprising rotating said transmitter/sensor unit relative to said vehicle.

5. The method of claim 1 further comprising initially determining reference positions of said plurality of reflectors.

6. The method of claim 1 further comprising controlling the heading of said vehicle using control directives generated in response to said navigational data elements.

7. The method of claim 6 wherein said navigational data elements are computed remotely from said vehicle.

8. The method of claim 7 wherein the control directives are generated remotely from said vehicle and thereafter communicated to said vehicle.

9. A device for navigating a vehicle by a laser-optical method comprising:

a transmitter/sensor means mounted on said vehicle for transmitting a beam of light away from said vehicle and for receiving reflected light;

a plurality of reflector means disposed a distance away from said transmitter/sensor means for reflecting said beam of light back to said transmitter/sensor means;

an elevation angle measuring means for measuring elevation angles of said vehicles from said reflected light;

an azimuth angle measuring means for measuring azimuth angles of said vehicle from said reflected light; and

a computing means for compiling said elevation and azimuth angles received from said elevation and azimuth angle measuring means and computing navigational data elements for said vehicle from said compiled elevation and azimuth angles, said elements comprising a position in three-dimensional coordinates, a heading, a pitch angle and a roll angle, and wherein said elements may be used to navigate said vehicle.

10. The apparatus of claim 9 further comprising means for displaying said navigational data elements.

11. The apparatus of claim 9 wherein said means for transmitting said beam of light comprises a plurality of laser diodes, each laser diode having a beam focusing lens associated therewith, and a collimation lens located in front of said beam focusing lenses and being common to all said laser diodes and beam focusing lenses.

12. The apparatus of claim 9 wherein said elevation angle measuring means comprises a camera lens positioned to receive incoming reflected light, and a photo diode array located behind said camera lens in a focal plane of said camera lens.

13. The apparatus of claim 9 wherein said beam of light is pulsed.

14. The apparatus of claim 9 wherein said beam of light is in a shape of a vertical fan.

15. The apparatus of claim 9 wherein said transmitter/sensor means rotates relative to said vehicle.

16. The apparatus of claim 9 further comprising means for controlling the heading of said vehicle using control directives generated by said computing means in response to said navigational data elements.

17. The apparatus of claim 9 wherein said computing means is remote from said vehicle.

18. The apparatus of claim 17 further comprising a communication means for communicating between said remote computing means and said vehicle.

19. The apparatus of claim 9 wherein said computing means comprises a first computer compiling said elevation angles received from said elevation angle measuring means and a second computer for computing said navigational data elements for said vehicle from said compiled elevation angles and said azimuth angles.

20. The apparatus of claim 19 wherein said second computer is remote from said vehicle.