OPTICAL LENS DOCKING SYSTEM

• US 3,729,262 A
• Filed: 07/20/1971
• Issued: 04/24/1973
• Est. Priority Date: 07/20/1971
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Edwin E. Snead, Jay B. Pitkow
• Inventors: Snead, Edwin E., Pitkow, Jay B.
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Godwin, Paul K.
• Application Number:
  US05/164,350
• Time in Patent Office: 644 Days
• Field of Search: 356/153,154 244/114 114/43.5 340/26
• US Class Current: 356/153
• CPC Class Codes: B64F 1/002 Taxiing aids
• CPC Class Codes: G08G 5/0026 located on the ground
• CPC Class Codes: G08G 5/065 Navigation or guidance aids, e.g. for taxiing or rolling

Abstract

A system is described which provides a visual display for the accurate guidance and docking of aircraft after landing. The display is also suitable for the visual alignment and guidance of other vehicles to a desired parking position. The system employs a combination of lenses and light sources arranged to create for the observer, information for center line steering, closing rate and stopping. In terms of aircraft docking, such information permits the pilot to dock his aircraft without the assistance of ground personnel.

Claims

1. An optical device for providing visual alignment and guidance to enable an observer to pursue a prescribed path of travel and to stop at a predetermined point along said path comprising, a center line module having at least first and second light sources and a first lens system positioned with respect to said light sources to form respective images thereof, means within said center line module for separating the images of said light sources as seen by said observer, said first light source being positioned a first distance from said first lens system whereby the image formed thereof as viewed by said observer appears to remain stationary and serves as a datum bar, said second light source being positioned at a second distance from said first lens system whereby the image formed thereof serves as a center line bar which when viewed by said observer appears to be displaced with respect to said datum bar in proportion to the azimuthal deviation of said observer from said path of travel, the alignment of said center line bar with said datum bar by said observer being indicative of travel along said prescribed path, a stop bar module having at least a single light source and a second lens system positioned with respect thereto such that the image formed by said second lens system as seen by said observer serves as a stop bar, a stop cue positioned in predetermined relationship to said stop bar module, said stop bar appearing to said observer to be displaced from alignment with said stop cue in proportion to the observer'"'"''"'"'s distance from said predetermined stop point, the concurrent alignments by said observer of said center line bar with said datum bar in said center line module and said stop cue with said stop bar in said stop bar module being indicative of the attainment by said observer of said predetermined stop point along said prescribed path of travel.

2. An optical device as defined in claim 1 wherein said first lens system comprises a first lens so positioned with respect to said center line module first and second light sources that virtual images of said sources are formed, and a second lens positioned with respect to said first lens for diffusing the rays of light emerging from said first lens.

3. An optical device as defined in claim 2 wherein said first lens is a Fresnel lens and said second lens is a cylindrically ribbed lenticular for vertically diffusing said rays of light emerging from said Fresnel lens.

4. An optical device as defined in claim 1 wherein said second lens system comprises a first lens so positioned with respect to said stop bar module light source that a virtual image of said source is formed, and a second lens positioned with respect to said first lens for diffusing the rays of light emerging from said first lens.

5. An optical device as defined in claim 4 wherein said first lens is a Fresnel lens and said second lens is a cylindrically ribbed lenticular for horizontally diffusing said rays of light emerging from said Fresnel lens.

6. An optical device as defined in claim 4 wherein said stop bar module single light source is positioned a predetermined vertical distance off the optical axis of said Fresnel lens and a predetermined horizontal distance therefrom such that when said stop bar is viewed by said observer at a prescribed distance from the front of said device, said stop bar will be aligned with said stop cue.

7. An optical device as defined in claim 6 wherein said stop bar module comprises a second light source in addition to said single source, said sources being positioned in a vertical plane respectively above and below the optical axis of the Fresnel lens in said second lens system, the stop bar image derived from said first light source being visible exclusively to an observer situated below said optical device, and the stop bar image of said second light source being visible exclusively to an observer situated above said optical device.

8. An optical device as defined in claim 7 further including means for moving said stop bar module light sources along two axes, namely vertically to independently adjust the distance of each of said light sources from the Fresnel lens optical axis and horizontally to collectively aDjust the distance of the light sources from the Fresnel lens itself.

9. An optical device for assisting the docking of a vehicle by providing visual information to permit an observer to cause said vehicle to pursue a path of travel along a prescribed center line and to stop at a predetermined point along said line comprising a center line module having at least first and second light sources and a first lens system positioned with respect to said light sources to form respective images thereof, light baffle means situated within said center line module for separating the images of said light sources as seen by said observer, said first light source being positioned a first distance from said first lens system wherein the image formed thereof as viewed by said observer appears to remain stationary and serves as a vertical datum bar, said second light source being positioned at a second distance from said first lens system whereby the image formed thereof serves as a vertical center line bar, said vertical center line bar when viewed by said observer appearing to move horizontally with respect to said vertical datum marker in response to movement in a horizontal plane on either side of said center line by said observer, the alignment of said center line bar with said datum bar by said observer being indicative of travel along said prescribed center line, a stop bar module having at least a single light source and a second lens system positioned with respect thereto such that the image formed by said second lens system as seen by said observer serves as a horizontal stop bar, at least one mask section positioned adjacent said stop bar module and having the designation and associated stop cue of the vehicle being docked, said stop cue being positioned in predetermined relationship to said stop bar module, said horizontal stop bar appearing to said observer to move in a vertical direction in response to adjustment of the distance of said vehicle from said optical device, the concurrent alignments by said observer of said center line bar with said datum bar in said center line module and said stop cue with said stop bar in said stop bar module being indicative of the vehicle having attained said predetermined stop point along said prescribed center line.

10. An optical device as defined in claim 9 wherein said first lens system comprises ground glass inserts illuminated respectively by said center line module first and second light sources and serving as objectives for said first lens system, a Fresnel lens for forming virtual images of said light sources, and a cylindrically ribbed lenticular positioned with respect to said Fresnel lens and having its rib axes oriented horizontally to effect the vertical spreading of the light rays emerging from said Fresnel lens.

11. An optical device as defined in claim 10 further including a pair of narrow, band-like colored filter members positioned respectively at the horizontal extremities of said center line module, between said Fresnel lens and said cylindrically ribbed lenticular, the appearance of said center line bar at a predetermined one of said horizontal extremities as indicated by a change in the normal color of said bar to that of said filter, providing turn-in point information to said observer for insuring initial satisfactory alignment of said vehicle with said prescribed center line.

12. An optical device as defined in claim 11 further characterized in that said ground glass inserts in said first lens system have a spectral wavelength of 5,500 Angstroms.

13. An optical device as defined in claim 9 wherein said second lens system comprises at least one ground glass insert illuminated by said stop bar module light source and serving as the objective for said second lens system, a Fresnel lens for forming a virtual image of said light source, and a cylindrically ribbed lenticular positioned with respect to said Fresnel lens and having its rib axes oriented vertically to effect the horizontal spreading of the light rays emerging from said Fresnel lens.

14. An optical device as defined in claim 13 further characterized in that said ground glass insert in said second lens system has a spectral wavelength of 5,500 Angstroms.

15. An optical device as defined in claim 9 further characterized in that said mask section is of laminar construction comprising the alpha-numeric mask itself having the designations of the vehicles to be docked together with the associated stop cue symbols, said mask being inserted between an external matte-finish acrylic sheet to minimize solar reflections and an internal plastic sheet.

16. An optical device as defined in claim 15 further including means for illuminating said vehicle designations and associated stop cues in said mask section.

17. An optical device as defined in claim 9 further including means for adjusting the vertical position of said stop cue relative to the stop bar module display.

18. An optical device as defined in claim 17 wherein said means for adjusting the vertical position of said stop cue comprises a substantially opaque section having a translucent window therein, said window being displaced a predetermined distance from the horizontal axis of said section and forming said stop cue, means for mounting said section adjacent the designation of the vehicle being docked, respective different stop cue positions being effected by the rotation of said section through 180* at the time of said mounting.

19. An optical device as defined in claim 9 further including an automatic light intensity control circuit for increasing the light intensity of all of said light sources for high ambient light conditions and for decreasing said light intensity for low ambient light, whereby a proper contrast ratio is maintained between said optical device and the surrounding ambient light.

20. An optical device as defined in claim 19 wherein said light intensity control circuit comprises a gate-controlled full wave AC silicon switch having first, second and third terminals, a source of AC voltage having a pair of terminals, means coupling said switch first terminal to one of said pair of AC voltage terminals, the light sources in each of said modules being connected in series strings and the two series strings being connected in parallel with each other, means coupling the light source series/parallel arrangement between the other of said pair of AC voltage terminals and said switch second terminal, first and second potentiometers and a photocell, said first potentiometer being connected in parallel with the series arrangement of said photocell and said second potentiometer, means coupling said last-mentioned series/parallel arrangement between said switch second and third terminals.