Object tracking using optical correlation and feedback
View Patent ↗A motion-sensing device is used to track motion of an object. The motion-sensing device includes an optical correlator, a motor system and a controller. The optical correlator has an imager. The optical correlator provides a feedback signal that indicates motion of the object in at least one dimension based on detected movement of an image of the object from a first location within the imager to a second location within the imager. The motor system can move the imager. The controller receives the feedback signal from the optical correlator and uses the feedback signal to calculate motion of the object and to control the motor system to move the imager so that the image of the object is returned to the first location within the imager.
1. A motion-sensing device used to track motion of an object, comprising:
a first optical correlator having a first imager, the first optical correlator providing a first feedback signal that indicates motion of the object exclusively in first and second directions based on detected movement of a first image of the object from a first location within the first imager to a second location within the first imager, the first and second directions being perpendicular to each other;
a first motor system that can move the first imager;
a second optical correlator having a second imager, the second optical correlator providing a second feedback signal that indicates motion of the object exclusively in a third direction based on detected movement of a second image of the object from a first location within the second imager to a second location within the second imager, the third direction being perpendicular to the first and second directions;
a second motor system that can move the second imager; and
a controller that receives the first feedback signal from the first optical correlator and uses the feedback signal to calculate motion of the object and to control the first motor system to move the first imager so that the image of the object is returned to the first location within the imager, wherein the controller receives the second feedback signal from the second optical correlator and uses the second feedback signal to calculate motion of the object in the third direction and to control the second motor system to move the second imager.
2. A motion-sensing device as in claim 1 wherein the first location of the first image of the object is a center of the first imager.
3. A motion-sensing device as in claim 2 wherein the first motor system is configured to move the first imager in the first direction and to move the first imager in the second direction to maintain the first image of the object centered within the first imager.
4. A motion-sensing device as in claim 1 wherein the first motor system physically moves the first imager by rotating the first optical correlator around two perpendicular axes.
5. A motion-sensing device as in claim 1 wherein the first imager is an array of photodetectors.
6. A motion-sensing device as in claim 1 wherein the first motor system includes two motors, a first motor rotates the first optical correlator around a first axis, and a second motor rotates the first optical correlator around a second axis, the first axis being perpendicular to the second axis.
7. A method for tracking motion of an object, comprising:
detecting movement of a first image of the object from a first location within a first imager to a second location within the imager;
generating a first feedback signal that indicates motion of the object exclusively in a first and second direction based on the detected movement of the first image of the object from the first location to the second location within the first imager, the first and second directions being perpendicular to each other;
using the first feedback signal to calculate motion of the object and to control a first motor system to move the first imager so that the first image of the object is returned to the first location within the first imager;
detecting movement of a second image of the object from a first location within a second imager to a second location within the second imager;
generating a second feedback signal that indicates motion of the object exclusively in a third direction based on the detected movement of the second image of the object from the first location to the second location within the second imager, the third direction being perpendicular to the first and second directions; and
using the second feedback signal to calculate motion of the object in the third direction and to control a second motor system to move the second imager so that the second image of the object is returned to the first location within the second imager.
8. A method as in claim 7 wherein the first location of the first image of the object is a center of the first imager.
9. A method as in claim 7 wherein the first motor system moves the first imager in the first direction and moves the first imager in the second direction to maintain the first image of the object centered within the first imager.
10. A method as in claim 7 wherein the first motor system physically moves the first imager by rotating the first imager around two perpendicular axes.
11. A method as in claim 7 wherein the first imager is an array of photodetectors.
12. A method as in claim 7 wherein the motor system includes two motors, a first motor rotates the first imager around a first axis, and a second motor rotates the first imager around a second axis, the first axis being perpendicular to the second axis.
13. A motion-sensing device used to track motion of an object, comprising:
means for providing a first feedback signal that indicates motion of the object exclusively in first and second directions based on detected movement of a first image of the object from a first location within a first imager to a second location within the first imager, the first and second directions being perpendicular to each other;
means for moving the first imager;
means for using the first feedback signal to calculate motion of the object and to control the means for moving the first imager to move the first imager so that the first image of the object is returned to the first location within the first imager;
means for providing a second feedback signal that indicates motion of the object exclusively in a third direction based on detected movement of a second image of the object from a first location within a second imager to a second location within the second imager, the third direction being perpendicular to the first and second directions;
means for moving the second imager; and
using the second feedback signal to calculate motion of the object in the third direction and to control a second motor system to move the second imager so that the second image of the object is returned to the first location within the second imager.
14. A motion-sensing device as in claim 13 wherein the first location of the first image of the object is a center of the first imager.
15. A motion-sensing device as in claim 14 wherein the first motor system is configured to move the first imager in the first direction and to move the first imager in the second direction to maintain the first image of the object centered within the first imager.
16. A motion-sensing device as in claim 13 wherein the means for moving the first imager physically moves the first imager by rotating a housing of the first imager around two perpendicular axes.
17. A motion-sensing device as in claim 13 wherein the first imager is an array of photodetectors.
18. A motion-sensing device as in claim 13 wherein the means for moving the first imager includes two motors, a first motor rotates a housing for the first imager around a first axis, and a second motor rotates the housing for the first imager around a second axis, the first axis being perpendicular to the second axis.