Rod shaped device and data acquisition apparatus for determining the position and orientation of an object in space

• US 5,818,424 A
• Filed: 10/19/1995
• Issued: 10/06/1998
• Est. Priority Date: 10/19/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Korth, Hans-Erdmann
• Primary Examiner(s): LAO, LUNYI
• Application Number:
  US08/545,063
• Time in Patent Office: 1,083 Days
• Field of Search: 345/158, 345/156, 345/157, 345/179, 345/145, 382/184, 382/312, 382/313
• US Class Current: 345/158
• CPC Class Codes: G06F 3/0325 using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

A rod-shaped device for spatial data acquisition includes a shank (1) with at least two separated, substantially identical marker field structures (3, 4) on the surface of the shank (1). The marker field structures (3, 4) are resolvable for imaging purposes by an optical position and orientation determination system for determining the position and orientation of an object in space. That system includes imaging apparatus (5) with a field of vision containing the rod-shaped device to capture position data of the rod shaped device. A computer (6) connected to the image apparatus receives the position data and calculates the position and orientation of the object in space.

Claims

1. A rod-shaped device for spatial data acquisition comprising a shank with a tip end, with at least two separated non-emitting marker field structures on the surface of said shank, said marker field structures being resolvable by imaging means for measurement of both the length and orientation of said rod-shaped device.

2. A rod-shaped device for spatial data acquisition comprising a shank with a tip end, with at least two separated marker field structures on the surface of said shank, said marker field structures being resolvable by imaging means for measurement of both the length and orientation of said rod-shaped device wherein, each of said at least two separated marker field structures includes two spaced sets of one or more identical line grid patterns, said line grid patterns containing a defined number of circumferential bright and dark lines.

3. The rod-shaped device of claim 2 wherein:

each of said at least two separated marker field structures further comprises a sequence of non-circumferential bright and dark sectors between the two spaced sets.

4. The rod-shaped device of claim 3 wherein:

each of said at least two separated marker field structures includes a different sequence of said non-circumferential bright and dark sectors.

5. The rod-shaped device of claim 3 wherein;

the distance L between the centers of said at least two separated marker field structures is greater than the lengths L1 and L2 of said two separated marker field structures and greater than the widths W1 and W2 of said bright and dark sectors.

6. An optical position and orientation determination system for determining the position and orientation of an object in space comprising:

a rod-shaped device with at least two separated marker field structures on the surface thereof along the length of the rod-shaped device, said marker field structures being resolvable by imaging means, wherein said at least two separated sets of marker field structures includes grid line pattern having a number of circumferential bright and dark lines on the surface of said rod-shaped device, said marker field structures being resolvable for measurement of both the length and orientation of said rod shaped device;

imaging means having a field of vision containing said rod-shaped device, said imaging means having image acquisition means for measuring position data of said device using said separated marker field structures; and

computer means connected to said imaging means for receiving said measured data and for calculating the position and orientation of said object in space.

7. The optical position and orientation determination system of claim 6 wherein said rod-shaped device includes at least two separated sets of marker field structures on the surface of said shank, said marker field structures being resolvable by imaging means for measurement of both the length and orientation of said rod-shaped device.

8. The optical position and orientation determination system of claim 6 wherein:

each of said at least two separated sets of marker field structures further comprises a sequence of non-circumferential bright and dark sectors.

9. The optical position and orientation determination system of claim 8 wherein:

each of said at least two separated marker field structures includes a different sequence of said non-circumferential bright and dark sectors.

10. The optical position and orientation determination system of claim 9 wherein:

the distance L between the centers of said at least two separated sets of marker field structures is greater than the lengths L1 and L2 of said two separated sets of marker field structures and greater than the widths W1 and W2 of said bright and dark sectors.

11. The optical position and orientation determination system of claim 10, wherein said imaging means comprises a video camera.

12. A method for determining the position and orientation of an object in space with an optical position orientation determination system comprising the steps of:

imaging a rod-shaped device with at least two separated marker field structures along its length each separated marker field structure having bright and dark sectors;

providing a distance L along the rod-shaped device between the centers of said at least two separated marker field structures;

providing a widths W1 and W2 to said bright and dark sectors of the marker field structure;

extracting position data (X1, Y1) of the center of the first marker field structure;

extracting position data (X2, Y2) of the center of the second marker field structure;

extracting the visible distance D between the centers of said at least two separated marker field structures;

extracting the visible distances D1 and D2 between the centers of the identical line grid patterns of each marker field structure;

calculating the coordinates X and Y of the center between said at least two separated marker field structures;

calculating the pitch angle ψ

;

calculating the yaw angle φ

; and

calculating the roll angle χ

.

13. The method of claim 12 wherein said imaging the rod-shaped device comprises:

defining a reference plane at a distance Zo from an imaging means; and

defining the visible distance Lo between the centers of said at least two separated marker field structures at said defined distance Zo.

14. The method of claim 13 further comprising calculating the coordinate Z of the center between said at least two separated marker field structures.

15. A method for determining the position and orientation of an object in space with an optical position orientation determination system comprising the step of:

imaging a rod-shaped device with at least two separated marker field structures along its length each separated marker field structure having bright and dark sectors at the center of the marker field structures;

providing a distance L along the rod-shaped device between the centers of said at least two separated marker field structures which distance L is longer than the lengths L1 and L2 of the marker field structures;

providing widths W1 and W2 for said bright and dark sectors of the marker field structure;

extracting from the image position data (X1, Y1) for the center of the first marker field structure;

extracting from the image position data (X2, Y2) for the center of the second marker field structure;

extracting the visible distance D between the centers of said at least two separated marker field structures;

extracting the visible distance D1 and D2 between the centers of the identical line grid patterns of each marker field structure;

calculating the coordinates X and Y of the center between said at least two separated marker field structures;

calculating the pitch angle ψ

;

calculating the yaw angle φ

; and

calculating the roll angle χ

.

16. The method of claim 15 wherein said imaging the rod-shaped device comprises:

defining a reference plane at a distance Zo from an imaging means; and

defining the visible distance Lo between the centers of said at least two separated marker field structures at said defined distance Zo.

17. The method of claim 16 further comprising calculating the coordinate Z of the center between said at least two separated marker field structures.

18. An optical position and orientation determination system for determining the position and orientation of an object in space comprising:

a rod-shaped device with at least two separated reflective marker field structures on the surface thereof along the length of the rod-shaped device, said marker field structures being resolvable by imaging means;

imaging means having a field of vision containing said rod-shaped device, said imaging means having image acquisition means for measuring position data of said device using said separated marker field structures; and

computer means connected to said imaging means for receiving said measured data and for calculating the position and orientation of said object in space.