Sensing device and method for measuring position and orientation relative to multiple light sources

• US 20050213109A1
• Filed: 03/25/2005
• Published: 09/29/2005
• Est. Priority Date: 03/29/2004
• Status: Abandoned Application

• Current Assignee: Evolution Robotics Inc. (iRobot Corporation)
• Original Assignee: Evolution Robotics Inc. (iRobot Corporation)
• Inventors: Kerekes, Thomas, Schell, Steve, Brown, Joe, Witman, Robert
• Application Number:
  US11/090,405
• Publication Number:
  US 20050213109A1
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 2013/468 by Triangulation, i.e. two antennas or two sensors determine separately the bearing, direction or angle to a target, whereby with the knowledge of the baseline length, the position data of the target is determined
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements

Abstract

A sensing device and method of estimating the position and orientation of an object with respect to a local or a global coordinate system is disclosed. The method and device include one or more optical sensor, a signal processing circuitry and a signal processing algorithm to determine the position and orientation. A sensor is positioned within the housing. At least one of the optical sensors used in the method and system outputs information based at least in part on the detection of the signal of one or more light sources.

Claims

1. A sensing system for estimating position and orientation of an object relative to a global reference frame based on a plurality of projected light sources, comprising:

a light sensitive position sensor wherein said light sensitive position sensor is capable of generating a signal; and

a processor wherein said processor is in communication with said position sensor through said signal.

2. The system of claim 1, wherein said light sensitive position sensor comprises a 2-dimensional position-sensitive detector (“

PSD”

).

3. The system of claim 1, wherein said light sensitive position sensor comprises a segmented photodiode with more than one light sensitive segment.

4. The system of claim 1, wherein said light sensitive position sensor further comprises:

a camera; and

a processor unit.

5. The system of claim 1, wherein said light sensitive position sensor is a light-focusing device wherein said light focusing device is capable of permitting a controlled amount of image blur, providing a field of view and providing a controlled amount of light.

6. The system of claim 1, wherein said processor generates said position and orientation by extracting frequency components from said signal.

7. The system of claim 6, wherein said processor extracts said frequency components by using time-frequency transform algorithm.

8. The system of claim 1, wherein said processor comprises:

an amplifier;

an digital converter;

a signal processor; and

an input-output communication channel.

9. A method of estimating position and orientation of an object relative to a global reference frame based on a plurality of projected light sources, comprising:

focusing a plurality of images from said projected light sources onto an optical sensor;

converting said images into electrical signals representing centroids of said projected light sources;

extracting a plurality of position information of said projected light sources from, at least in part, said electrical signal; and

calculating said position and orientation of said optical sensor from said position information in said global reference frame based on said light sources.

10. The method of claim 9, wherein converting said images comprises reading said electrical signal from an imager.

11. The method of claim 10, wherein converting said images comprises reading electrical signals from said imager and a lens.

12. The method of claim 11, wherein said image comprises reading said electrical signals from said imager, an optical filter and said lens.

13. The method of claim 9, wherein extracting said plurality of position information comprises decomposing said electrical signals into a plurality of frequency components.

14. The method of claim 9, wherein extracting said position information comprises decomposing said electrical signals into a plurality of frequency components and searching various frequencies for components that satisfy a pre-determined criteria.

15. A sensing system for providing position and orientation of an object to communicate with a control unit wherein said control unit provides instructions to move said object autonomously, comprising:

a light sensitive position sensor wherein said position sensor is capable of generating a signal;

a processor wherein said processor is in communication with said light sensitive position sensor through said signal;

a plurality of projected light sources;

a communication channel to said control unit; and

a memory to store output information from said processor.

16. The system of claim 15, wherein said light sensitive position sensor comprises a 2-dimensional position-sensitive detector (“

PSD”

).

17. The system of claim 15, wherein said light sensitive position sensor comprises a segmented photodiode with more than one light sensitive segment.

18. The system of claim 15, wherein said light sensitive position sensor further comprises:

a camera; and

a processor unit.

19. The system of claim 15, wherein said light sensitive position sensor is a light-focusing device wherein said light focusing device is capable of permitting a controlled amount of image blur, providing a field of view and providing a controlled amount of light.

20. The system of claim 15, wherein said processor provides said position and orientation of said object by extracting frequency components from said signal.

21. The system of claim 20, wherein said processor extracts said frequency components by using time-frequency transform algorithm.

22. A sensing system for providing position and orientation of an autonomous vehicle in an enclosure environment, comprising:

a light source;

a plurality of light spots wherein said light spots illuminating at frequencies distinct from one another;

a position sensitive detector wherein said PSD capture at least two images corresponding to said light spots;

a plurality of electrical signals produced by said PSD corresponding to physical positions on PSD of said images;

a signal processor wherein said signal processor converts said electric signals into digital representations of said positions of said images;

a digital processor wherein said digital processor produces said position and orientation from said digital representation; and

a communication channel wherein said communication channel provides said position and orientation to said vehicle.