Wireless position and orientation detecting system

• US 6,388,755 B1
• Filed: 11/16/1999
• Issued: 05/14/2002
• Est. Priority Date: 12/03/1998
• Status: Expired due to Fees

• Current Assignee: Advanced Optical Technologies, Inc.
• Original Assignee: Advanced Optical Technologies, Inc.
• Inventors: Zhao, Ying, Chao, Yong-Sheng
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Nguyen, Tu T.
• Application Number:
  US09/441,285
• Time in Patent Office: 910 Days
• Field of Search: 356/139-1-1, 356/141--14, 356/400, 356/614-624, 250/206.1, 250/559.31
• US Class Current: 356/614
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates

Abstract

An apparatus and method for wirelessly determining position and orientation of a first object relative to a second object in six dimensions, including one or more recording assemblies and one or more identification-coded or orientation-coded optical transponders. The positions of the recording assemblies are fixed relative to the first object and the transponders are fixed relative to the second object. A light source in each recording assembly emits light into space that is received, modulated, and retransmitted back by each transponder to a photodetector assembly in the recording assembly. The identification-coded optical transponder modulates the retransmitted light with a unique fixed code. The orientation-coded optical transponder modulates the retransmitted light with a unique fixed code that depends upon the direction of the incident light. The photodetector assemblies provide one or two independent position parameters for each transponder and two independent orientation parameters for each orientation-coded transponder. The system includes a combination of recording assemblies and transponders that provides at least six independent measured parameters.

Claims

1. A direct input system for determining six dimensions of position and orientation of a movable object relative to a known location, said system comprising:

(a) a first recording assembly fixed relative to said known location and including a first light source and a linear photodetector assembly, said first light source emitting first source light to said movable object;

(b) a second recording assembly fixed relative to said known location and including a second light source and a two-dimensional photodetector assembly, said second light source emitting second source light to said movable object;

(c) an optical transponder fixed to said movable object, said optical transponder receiving, modulating, and retransmitting said first source light as first retransmitted light with a first modulation code representing the direction of said first location relative to said movable object, and said optical transponder receiving, modulating, and retransmitting said second source light as second retransmitted light with a second modulation code representing the direction of said second location relative to said movable object;

(d) said linear photodetector assembly receiving said first retransmitted light, and providing said first modulation code and a one-dimensional coordinate representing one dimension of the direction from which said first retransmitted light is received;

(e) said two-dimensional photodetector assembly receiving said second retransmitted light, and providing said second modulation code and a two-dimensional coordinate pair representing the direction from which said second retransmitted light is received; and

(f) a means for calculating said six dimensions of position and orientation of said movable object relative to said known location from said one-dimensional coordinate, said first modulation code, said two-dimensional coordinate pair, and said second modulation code.

2. A direct input system for determining six dimensions of position and orientation of a movable object relative to a known location, said system comprising:

(a) a first optical transponder fixed relative to said known location;

(b) a second optical transponder fixed relative to said known location;

(c) a third optical transponder fixed relative to said known location;

(d) a recording assembly fixed to said movable object and including a light source and a two-dimensional photodetector assembly, said light source emitting source light to said first optical transponder, said second optical transponder, and said third optical transponder;

(e) said first optical transponder receiving, modulating, and retransmitting said source light as first retransmitted light with a first modulation code;

(f) said second optical transponder receiving, modulating, and retransmitting said source light as second retransmitted light with a second modulation code different from said first modulation code;

(g) said third optical transponder receiving, modulating, and retransmitting said source light as third retransmitted light with a third modulation code different from said first modulation code and said second modulation code;

(h) said two-dimensional photodetector assembly receiving said first retransmitted light, and providing said first modulation code and a first two-dimensional coordinate pair representing the direction from which said first retransmitted light is received;

(i) said two-dimensional photodetector assembly receiving said second retransmitted light, and providing said second modulation code and a second two-dimensional coordinate pair representing the direction from which said second retransmitted light is received;

(j) said two-dimensional photodetector assembly receiving said third retransmitted light, and providing said third modulation code and a third two-dimensional coordinate pair representing the direction from which said third retransmitted light is received; and

(k) a means for calculating said six dimensions of position and orientation of said movable object relative to said known location from said first two-dimensional coordinate pair, said first modulation code, said second two-dimensional coordinate pair, said second modulation code, said third two-dimensional coordinate pair, and said third modulation code.

3. A direct input system for determining six dimensions of position and orientation of a movable object relative to a known location, said system comprising:

(a) a first recording assembly fixed relative to said known location and including a first light source and a first linear photodetector assembly, said first light source emitting first source light to said movable object;

(b) a second recording-assembly fixed relative to said known location and including a second light source and a second linear photodetector assembly, said second light source emitting second source light to said movable object;

(c) an optical transponder fixed to said movable object, said optical transponder receiving, modulating, and retransmitting said first source light as first retransmitted light with a first modulation code representing the direction of said first location relative to said movable object, and said optical transponder receiving, modulating, and retransmitting said second source light as second retransmitted light with a second modulation code representing the direction of said second location relative to said movable object;

(d) said first linear photodetector assembly receiving said first retransmitted light, and providing said first modulation code and a first one-dimensional coordinate representing one dimension of the direction from which said first retransmitted light is received;

(e) said second linear photodetector assembly receiving said second retransmitted light, and providing said second modulation code and a second one-dimensional coordinate representing one dimension of the direction from which said second retransmitted light is received; and

(f) a means for calculating said six dimensions of position and orientation of said movable object relative to said known location from said first one-dimensional coordinate, said first modulation code, said second one-dimensional coordinate, and said second modulation code.

4. A direct input system for determining six dimensions of position and orientation of a movable object relative to a known location, said system comprising:

(a) a first optical transponder fixed relative to said known location;

(b) a second optical transponder fixed relative to said known location;

(c) a recording assembly fixed to said movable object and including a light source and a linear photodetector assembly, said light source emitting source light to said first optical transponder and said second optical transponder;

(d) said first optical transponder receiving, modulating, and retransmitting said source light as first retransmitted light with a first modulation code representing the direction of said movable object relative to said first optical transponder;

(e) said second optical transponder receiving, modulating, and retransmitting said source light as second retransmitted light with a second modulation code representing the direction of said movable object relative to said second optical transponder;

(f) said linear photodetector assembly receiving said first retransmitted light, and providing said first modulation code and a first one-dimensional coordinate representing one dimension of the direction from which said first retransmitted light is received;

(g) said linear photodetector assembly receiving said second retransmitted light, and providing said second modulation code and a second one-dimensional coordinate representing one dimension of the direction from which said second retransmitted light is received; and

(h) a means for calculating said six dimensions of position and orientation of said movable object relative to said known location from said first one-dimensional coordinate, said first modulation code, said second one-dimensional coordinate, and said second modulation code.

5. A direct input system for determining six dimensions of position and orientation of a movable object relative to a known location, said system comprising:

(a) a first optical transponder fixed relative to said known location;

(b) a second optical transponder fixed relative to said known location;

(c) a recording assembly fixed to said movable object and including a light source and a two-dimensional photodetector assembly, said light source emitting source light to said first optical transponder and said second optical transponder;

(d) said first optical transponder receiving, modulating, and retransmitting said source light as first retransmitted light with a first modulation code representing the direction of said movable object relative to said first optical transponder;

(e) said second optical transponder receiving, modulating, and retransmitting said source light as second retransmitted light with a second modulation code that is constant regardless of the direction of said movable object relative to said second optical transponder;

(f) said two-dimensional photodetector assembly receiving said first retransmitted light, and providing said first modulation code and a first two-dimensional coordinate pair representing the direction from which said first retransmitted light is received;

(g) said two-dimensional photodetector assembly receiving said second retransmitted light, and providing said second modulation code and a second two-dimensional coordinate pair representing the direction from which said second retransmitted light is received; and

(h) a means for calculating said six dimensions of position and orientation of said movable object relative to said known location from said first two-dimensional coordinate pair, said first modulation code, said second two-dimensional coordinate pair, and said second modulation code.

6. A method for determining six dimensions of position and orientation of a first object relative to a second object, said method comprising the steps of:

(a) providing a first coordinate system fixed to said first object;

(b) providing a second coordinate system fixed to said second object;

(c) rigidly fixing at least one recording assembly to said first object, said at least one recording assembly having a light source that emits light as source light to said second object;

(d) providing said at least one recording assembly with a recording assembly reference point with a position and orientation that is known in said first coordinate system;

(e) rigidly fixing at least one optical transponder to said second object, said at least one optical transponder being selected from a group consisting of an identification-coded transponder and an orientation-coded transponder;

(f) providing said at least one optical transponder with a transponder reference point with a position and orientation that is known in said second coordinate system;

(g) said at least one optical transponder receiving, modulating, and retransmitting said source light as modulated light, each of said identification-coded transponders providing a unique fixed identification modulation code, and each of said orientation-coded transponders providing a unique orientation modulation code representing the direction of said first object relative to said second object;

(h) providing said at least one recording assembly with a photodetector selected from the group consisting of a photodetector that records one independent position parameter and a photodetector that records two independent position parameters, each of said photodetectors recording each of said orientation modulation codes as two independent angle parameters;

(i) providing said system with a combination of transponders and photodetectors capable of recording at least six independent parameters; and

(j) calculating said six dimensions of position and orientation of said first object relative to said second object from said six independent parameters, said unique modulation codes being used to distinguish said transponders from each other.

7. The method of claim 6 wherein said calculating of said six dimensions of position and orientation is comprised of the steps:

(a) writing an equation set that relates said six independent parameters to said six dimensions of position and orientation;

(b) compiling a reference table through calculation of expected measurement data points as a function of said six dimensions of position and orientation at a number of grid points; and

(c) using an iteration algorithm to calculate said six dimensions of position and orientation starting at a set of initial values of said six independent parameters obtained from said reference table.

8. The method of claim 7 wherein said reference table is inverted such that an inverted reference table lists said six dimensions of position and orientation in a numeric table form as a function of said six independent parameters, and said inverted table is used as said reference table.

9. The method of claim 7 wherein said method further comprises the step of using abundance measurements to check the consistency of said six dimensions of position and orientation.

10. A system for determining six dimensions of position and orientation of a first object relative to a second object, said system comprising:

(a) a first coordinate system fixed to said first object;

(b) a second coordinate system fixed to said second object;

(c) at least one recording assembly rigidly fixed to said first object, said at least one recording assembly having a light source that emits source light to said second object, said at least one recording assembly having a recording assembly reference point with a position and orientation that is known in said first coordinate system;

(d) at least one optical transponder rigidly fixed to said second object, said at least one transponder being selected from a group consisting of an identification-coded transponder and an orientation-coded transponder, said at least one transponder having a transponder reference point with a position and orientation that are known in said second coordinate system;

(e) said at least one transponder receiving, modulating, and retransmitting said source light as retransmitted light, each of said identification-coded transponders providing a unique fixed identification modulation code, and each of said orientation-coded transponders providing a unique orientation modulation code representing the direction of said first object relative to said second object;

(f) said at least one recording assembly having a photodetector selected from a group consisting of a photodetector that records one independent position parameter and a photodetector that records two independent position parameters, each of said photodetectors recording said orientation modulation code as two independent angle parameters;

(g) said system including a combination of transponders and photodetectors capable of recording at least six independent parameters, and either said first object has only one recording assembly or said second object has only one optical transponder; and

(h) a means for calculating said six dimensions of position and orientation of said first object relative to said second object from said six independent parameters;

said unique modulation codes being used to distinguish said at least one transponder from each other.

11. The system of the claim 10 wherein said at least one transponder is a single orientation-coded transponder, and said at least one recording assembly is two recording assemblies, a first of said recording assemblies having a photodetector that records one independent position parameter and said orientation modulation code, a second of said recording assemblies having a photodetector that records two independent position parameters and said orientation modulation code, said six independent parameters being selected from seven independent parameters consisting of said independent position parameter received by said first recording assembly, two angle parameters from said orientation modulation code received by said first recording assembly, said two independent position parameters received by said second recording assembly, and two angle parameters from said orientation modulation code received by said second recording assembly.

12. The system of the claim 10 wherein said at least one transponder is a single orientation-coded transponder, and said at least one recording assembly is two recording assemblies, each of said recording assemblies having a photodetector that records one independent position parameter and said orientation modulation code, said six independent parameters consisting of said independent position parameter received by said first recording assembly, two angle parameters from said orientation modulation code received by said first recording assembly, said independent position parameter received by said second recording assembly, and two angle parameters from said orientation modulation code received by said second recording assembly.

13. The system of the claim 10 wherein said at least one transponder is a first orientation-coded transponder and a second orientation-coded transponder, and said at least one recording assembly is one recording assembly having a photodetector that records one independent position parameter for each of said transponders and said orientation modulation code from each of transponders, said six independent parameters consisting of said independent position parameter of said first transponder, two angle parameters from said orientation modulation code of said first transponder, said independent position parameter from said second transponder, and two angle parameters from said orientation modulation code of said second transponder.

14. The system of the claim 10 wherein said at least one transponder is one orientation-coded transponder and one identification-coded transponder, and said at least one recording assembly is one recording assembly having a photodetector that records two independent position parameters and said orientation-coded transponder from said orientation-coded transponder and two independent position parameters and said identification modulation code from said identification-coded transponder, said six independent parameters consisting of said two independent position parameters of said orientation-coded transponder, two angle parameters from said orientation modulation code of said orientation-coded transponder, and said two independent position parameters from said identification-coded transponder.

15. The system of the claim 10 wherein said at least one transponder is a first identification-coded transponder, a second identification-coded transponder, and a third identification-coded transponder, and said at least one recording assembly is one recording assembly having a photodetector that records two independent position parameters for each of said transponders and said identification modulation code from each of said identification-coded transponders, said six independent parameters consisting of said two independent position parameters of said first transponder, said two independent position parameters from said second transponder, and said two independent position parameters from said third transponder.