Visually guided reaching
One useful task for a humanoid robot is to be able to reach towards objects within its immediate vacinity and try to grasp them. Physical manipulation helps the system to learn about the properties of objects, and to determine whether the object is passive (inanimate) or active (animate).
Rodney doesn't have any hands or pressure sensors yet, but I've been trying to get him to reach for objects which are close to the cameras. For this task the physical structure of the robot allows some crude shortcuts to be taken. When rodney observes moving objects his cameras pan and tilt to try to maintain the object within the centre of vision. When rodney's cameras are tilted downwards they can only view a limited area within the immediate vacinity of the robot, so its safe to assume that any movement observed is within close proximity. One of the arms is then moved to try to intercept the object, using the already calculated centre of motion value to guide it into the right area. This seems to be a crude but effective mechanism allowing the robot to reach for objects. A more sophisticated method would be to use the stereo matching to calculate distance and shape more accurately.
- Bob
http://www.fuzzgun.btinternet.co.uk/rodney18.jpg
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