In this paper we describe a control methodology for catching a fast moving object with a robot manipulator, where visual information is employed to track the trajectory of the target. Sensing, planning and control are performed in real-time to cope with possible unpredictable trajectory changes of the moving target, and prediction techniques are adopted to compensate the time delays introduced ...

We have introduced the weight of a group which has a presentation with number of relations is at most the number of generators. We have shown that the number of facets of any contracted pseudotriangulation of a connected closed 3-manifold M is at least the weight of the fundamental group of M . This lower bound is sharp for the 3-manifolds RP, L(3, 1), L(5, 2), S1 × S1 × S1, S2 × S1, S×− S1 and...

We consider closed topological 4-manifolds M $M$ with universal cover S 2 × ${S^2\times {S^2}}$ and Euler characteristic χ ( ) = 1 $\chi (M) 1$ . All such manifolds π ≅ Z / 4 $\pi =\pi _1(M)\cong {\mathbb {Z}/{4}}$ are homotopy equivalent. In this case, we show that there four homeomorphism types, propose a candidate for smooth example is not homeomorphic to the geometric quotient. If \cong \ma...