System and method for detecting and tracking a curvilinear object in a three-dimensional space
A system for detecting and tracking a curvilinear object in a three-dimensional space includes an image acquisition system including a video camera arranged to acquire a video image of the curvilinear object and output a corresponding video signal, the video image comprising a plurality n of image frames each at a respective time t i , where i=1, 2, . . . , n; and a data processing system adapted to communicate with the image acquisition system to receive the video signal. The data processing system is configured to determine a position, orientation and shape of the curvilinear object in the three-dimensional space at each time t i by forming a computational model of the curvilinear object at each time t i such that a projection of the computation model of the curvilinear object at each time ti onto a corresponding frame of the plurality of image frames of the video image matches a curvilinear image in the frame to a predetermined accuracy to thereby detect and track the curvilinear object from time t 1 to time t n .
1. A robotic system, comprising:
a manipulator assembly;
a manipulator control system configured to communicate with said manipulator assembly; and
a system for detecting and tracking a curvilinear object in a three-dimensional space configured to communicate with said manipulator control system,
wherein said system for detecting and tracking a curvilinear object in a three-dimensional space comprises:
an image acquisition system comprising a video camera arranged to acquire a video image of said curvilinear object and output a corresponding video signal, said video image comprising a plurality n of image frames each at a respective time t i , where i=1, 2, . . . , n; and
a data processing system adapted to communicate with said image acquisition system to receive said video signal,
wherein said data processing system is configured to determine a position, orientation and shape of said curvilinear object in said three-dimensional space at each time t i by forming a computational model of said curvilinear object at each time t i such that a projection of said computation model of said curvilinear object at each time t i onto a corresponding frame of said plurality of image frames of said video image matches a curvilinear image in said frame to a predetermined accuracy to thereby detect and track said curvilinear object from time t 1 to time t n .
2. A robotic system according to claim 1 , wherein said manipulator assembly comprises at least one manipulator arm.
3. A robotic system according to claim 2 , wherein said data processing system is further configured to receive information concerning a location of at least a portion of said manipulator arm from said manipulator control system to be used in determination a position, orientation and shape of said curvilinear object in said three-dimensional space at each time t i .
4. A robotic system according to claim 2 , wherein said manipulator control system is configured to receive information concerning at least one of said position, orientation or shape of said curvilinear object from said system for detecting and tracking said curvilinear object to at least help guide said manipulator arm to perform an automated or semi-automated task on said curvilinear object.
5. A robotic system according to claim 1 , wherein said computational model is a non-uniform rational B-spline model.
6. A robotic system according to claim 1 , wherein said curvilinear object comprises a texture that is visible in said video image and said data processing system is further configured to determine said texture of said curvilinear object in said three-dimensional space at each time t i by including texture in said computational model of said curvilinear object at each time t i .
7. A robotic system according to claim 6 , wherein said texture is a color pattern such that some portions of said curvilinear object are distinguishable from other portions based on differences in color.
8. A robotic system according to claim 1 , wherein said curvilinear object has a substantially invariant length and said computational model of said curvilinear object includes a constant-length constraint on the modeled curvilinear object.
9. A robotic system according to claim 1 , wherein said video camera is a stereo video camera arranged to acquire a stereo video image of said curvilinear object and output a corresponding stereo video signal, said stereo video image comprising a plurality n stereo pairs of image frames each at a respective time t i , where i=1, 2, . . . , n,
wherein said data processing system is adapted to communicate with said image acquisition system to receive said stereo video signal,
wherein said data processing system is configured to determine a position, orientation and shape of said curvilinear object in said three-dimensional space at each time t i by forming a computational model of said curvilinear object at each time t i such that a projection of said computation model of said curvilinear object at each time t i onto a corresponding stereo pair of frames of said plurality of stereo pairs of image frames of said stereo video image matches a two-dimensional curvilinear image in said stereo pair of frames to a predetermined accuracy to thereby detect and track said curvilinear object from time t 1 to time t n .