Docking alignment system

• US 4,890,918 A
• Filed: 09/15/1988
• Issued: 01/02/1990
• Est. Priority Date: 09/15/1988
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Monford, Leo G.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US07/246,595
• Time in Patent Office: 474 Days
• Field of Search: 356/138, 356/150, 356/152, 356/153, 356/399, 244/161, 358/103
• US Class Current: 356/150
• CPC Class Codes: B64G 1/646 Docking or rendezvous systems refueling in space B64G1/4024
• CPC Class Codes: G01B 11/272 using photoelectric detection means
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems

Abstract

Improved techniques are provided for alignment of two objects. The present invention is particularly suited for three-dimensional translation and three-dimensional rotational alignment of objects in outer space. A camera 18 is fixedly mounted to one object, such as a remote manipulator arm 10 of the spacecraft, while the planar reflective surface 30 is fixed to the other object, such as a grapple fixture 20. A monitor 50 displays in real-time images from the camera, such that the monitor displays both the reflected image of the camera and visible markings on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm 10 manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

Claims

1. Apparatus for real-time alignment of a first object with respect to a second object, the apparatus comprising:

camera means mounted to the first object and having an optical axis fixed with respect to the first object;

a reflective surface fixedly mounted to the second object and having a visible pattern thereon; and

monitor means for displaying in real-time images from the camera means and having a point optically fixed with respect to the optical axis of the camera means, such that the monitor means displays both the reflected image of the camera means and the visible pattern on the reflective surface each in relation to the fixed point on the monitor means when the reflective surface is perpendicular to the optical axis of the camera means.

2. The apparatus as defined in claim 1, wherein the monitor means displays an alignment image fixed with respect to the optical axis of the camera means, and the image of the visible pattern on the reflective surface is aligned on the monitor means with the alignment image when the first object is rotationally rolled into alignment with the second object.

3. The apparatus as defined in claim 1, wherein the reflective surface is a planar surface.

4. The apparatus as defined in claim 2, wherein the visible pattern on the reflective surface is of a preselected size, and a proportional size of the image of the visible pattern on the monitor means corresponds to a distance the camera means is spaced from the reflective surface.

5. The apparatus as defined in claim 4, wherein the preselectively sized visible pattern on the reflective surface comprises:

cross hairs defining a centerpoint for the reflective surface; and

a two-dimensional image of a predetermined size.

6. The apparatus as defined in claim 5, wherein the two-dimensional image encompasses the centerpoint of the reflective surface.

7. The apparatus as defined in claim 5, wherein the display of the two-dimensional image on the monitor means is of a preselected size when the camera means is spaced a preselected distance from the reflective surface.

8. The apparatus as defined in claim 1, wherein the fixed point on the monitor means is a cross hair point corresponding optically to the optical axis of the camera means.

9. Alignment apparatus for alignment and docking of a first object in outer space with respect to a second object in outer space, one of the first or second objects including power means for translational and rotational movement of the powered object with respect to the other object, the alignment apparatus comprising:

camera means mounted to the first object and having an optical axis fixed with respect to the first object;

a reflective surface fixedly mounted to the second object and having a visible pattern thereon; and

monitor means for displaying images from the camera means and having a fixed point corresponding optically to the optical axis of the camera means, such that the monitor means displays both the reflected image of the camera means and the visible pattern on the reflective surface each in a pre-selected relationship to the fixed point on the monitor means when (a) the reflective surface is prependicular to the optical axis of the camera means, and (b) the first object is at a selected rotational roll with respect to the second object.

10. The alignment apparatus as defined in claim 9, wherein the reflective surface is a planar surface.

11. The alignment apparatus as defined in claim 9, wherein the monitor means displays images from the camera means in real-time.

12. The alignment apparatus as defined in claim 9, wherein the visible pattern on the reflective surface is of a pre-selected size, and a proportional size of the image of the visible pattern on the monitor means corresponds to a distance the camera means is spaced from the reflective surface.

13. The alignment apparatus as defined in claim 12, wherein the preselectively sized visible marking pattern on the reflective surface comprises:

cross hairs defining a centerpoint for the reflective surface; and

a two-dimensional image of a predetermined size.

14. The alignment apparatus a defined in claim 13, wherein the two-dimensional image encompasses the centerpoint of the reflective surface.

15. The alignment apparatus as defined in claim 13, wherein the display of the two-dimensional image on the monitor means is of a preselected size when the camera means is spaced a preselected distance from the reflective surface.

16. The alignment apparatus as defined in claim 12, wherein the fixed point on the monitor means is a cross hair point formed by the intersection of non-parallel lines.

17. A method for aligning in real-time a first object with respect to a second object, the method comprising:

mounting a camera to the first object having an optical axis fixed with respect to the first object;

mounting a reflective surface to the second object having a visible pattern thereon;

displaying in real-time images from the camera on a monitor having a fixed point corresponding optically to the optical axis of the camera; and

maneuvering the first object with respect to the second object in response to the display on the monitor until the monitor displays both the reflected image of the camera and the visible pattern each in a preselected relationship with respect to the fixed point on the monitor indicative of the reflective surface being perpendicular to the optical axis of the camera.

18. The method as defined in claim 17, further comprising:

providing an alignment image on the monitor fixed with respect to the optical axis of the camera; and

rotating the first object with respect to the second object until the image of the visible pattern on the reflective surface is aligned on the monitor with the alignment image.

19. The method as defined in claim 17, wherein the step of maneuvering the first object with respect to the second object comprises:

moving the first object to alter the spacing between the camera and the reflective surface until the size of the reflected image of the camera on the monitor corresponds to a predetermined distance between the camera and the reflective surface.

20. The method as defined in claim 18, wherein the reflective surface is a planar surface having a pattern of a pre-selected size, and the step of maneuvering the first object with respect to the second object comprises:

moving the first object to alter the spacing between the camera and the reflective surface until the image of the pattern on the monitor corresponds to a predetermined distance between the camera and the reflective surface.